1980 US A.c. Compressor wiring a little help please
 

1980 U.S. 928 Air Con. Issues .
Air Con Compressor Hot Lead Wire Go's where ?
Mine is Broken off and I cant find where to hook it to

I See 3 Wires on top of the AC. Compressor . 2 go into the Compressor and 1 comes out and looks to be the " Hot Hook Up " when engaged Red in Color
It is clipped or broken off about 6 inches from the Pump and I see no wire hanging to Hook it to
Where should the wire hook up to ?
If anyone has a 1980 or 81 and could look under their Hood and look for the Hook up
a Photo would be a Big Help
( Compressor runs fine when I hook a hot lead to it )

Try Roger for the cd manuals. A red lead (2.5mm) goes from the Cooling motor directly to the control panel plug Q3 then to pin 87 of the cooling fan relay (XVIII). The fuse (#16) goes to pin 30 of the same relay providing the voltage to pin 87 when switch is on.

There a few dependent devices that are in the circuit...you need the current flow diagrams...

This info is for a '79, but should apply to you.

1979 is Different Says the Chart Say's 1978 to 1979 ( Rodgers chart )
78 & 79 has a AC Compressor Relay in Socket 16
" my 1980 has no Relay in Socket 16 and looks like it never had one " However I Bet wires run to the back of the socket
do you suggest I put a relay in socket 16 ? as if the Car was a 78 or 79 Yr Model .
Chart also says 1978 to 1981 : AC FAN RELAY Socket 9
You Mention " cooling fan relay (XVIII) " Well XV!!! ( 18 ) is my Washer Relay so that makes no sense to me or I am misunderstanding you totally
Your saying that the :
" AC CONDENSER FAN FUSE " # 16 on Panel is the Fuse for the AC Compressor then
Interesting ? they left out the word Compressor strange .
About this " A red lead (2.5mm) goes from the Cooling motor directly to the control panel plug Q3 "
I Don't know ( Forgive me ) what you mean by " Plug Q3 ? certainly you don't mean Socket 3 the window relay .
About the Cooling Motor by that do you mean the electric Fan in front of the Condenser ? or the Blower Fan
Sorry I am having trouble Understanding your Help But Thanks Much
I Can Download the Wiring Diagram next time I am on Hi Speed .
I See on a site that the AC Hot Wire should run in Front of the Right side Cam Cover But I don't see one .

My reference is the Porsche 1979 Current flow diagrams. I am using the words off of the diagrams and indicated that I am referring to a '79 which of course is a CIS maybe your MY is not CIS.

If you have the charts then just make sure you are wired up appropriately for you MY.

The reference to Plug Q3 is to the row of plugs with wires at the bottom of the Central electric panel (CEP)/fuse panel. The plugs go from left to right a-z (or so) usually the plugs have the Letter in black ink (handwritten) on them...I suppose you have not gotten into looking at the CEP in great detail yet...most everything electric will go through here to somewhere, though some do not.

Anybody have any idea where the Hot Wire for the AC Compressor should be found so I can hook it up to the Compressor ?
Example : wire should be coming from wiring loom top of motor next to Fuel Line near Passenger side Cam Cover
Example : Wire should hook up to 14 Pin connector Number ?
1980 US Model is the Year
I Hate to run a wire from a switch under the dash to the Compressor to turn on the Pump .
Surly someone must Know where this wire should be found .
Thanks if anyone knows
At this point I shall check out the AC Fan Relay in Socket # 9 as that's the only Relay Listed on the Chart related to the AC at all.
How some other year works well not help me set up the 1980 US Model unless Its exactly the same .

Well Thanks " JhwShark " to You I made Headway today I decided by Cooling Motor You Must Mean the AC Compressor. ( Not the Cooling Fan in front of the Condenser )
So I Removed My Fan Cooling Relay ( # 9 Socket in this 1980 )
and also the Q Plug at the Bottom of the Wiring Panel
I Jumped the 87 Pin and the 30 Pin of Socket 9 and nothing happened Key on or off
Then Leaving the Jumper I replaced the "Q" Plug and the Condenser Cooling Fan started running . Yea .
Then I Checked the Conductivity From " Q 3 " ( Left side of Q Plug ) to the Cooling Fan Relay and found " Conductivity so I knew I was on the right track THANKS
Then I Checked for Power at Q3 and discovered that with the AC Button Depressed ( engaged ) I had 9 / 10 Volts at Q3 motor off
Motor Running I had about 12.50 Volts
So Now I am on the right track !!!
I wish I knew where I should Look for the Q3 Wire under the Hood Like some wiring Loom or whatever . I Looked all around but see No Loose wires Hanging.
So Unless I go to a Porsche Salvage and see a 80 or 81 Model still Intact I can Look for the wire .
Looks Like However since I am Far up in N Cal I well have to do this as a fix for now .
Run a Wire from the Back Side of Q3 to the Compressor so that when I Press the AC Button the Compressor well Run.
Now I Expect this direct Wiring well mess up all the signals from what you call
the ' dependent devices '
"Quote "
" There a few dependent devices that are in the circuit...you need the current flow diagrams... "
...
I Expect the Cooling Fan in front of the Condenser well not come on until Device
perhaps Temperature controlled tells it to
I have read how some Wire the Cooling Fan to run at any time the AC is on
Perhaps I should do this ? Not sure about that
Any further Suggestions Much Appreciated
By The Way I am familiar with the Electric Panel Board and have worked with it front and Back But never really Dealt with the " Plugs on the bottom before "
Much Regards

Im not familiar with earlier models but,
There should be a switch on the drier that is most likely mounted in front of the radiator.
After it leaves the cab, goes to the thermal switch then the drier low pressure switch, this wire would go to the ac compressor.
Of course I could be wrong.

There are a few harness/looms that go from the CEP forward into the engine room. I would think, based upon the Cooling motors location, that it would come forward to where you see under the Hot/Jump post the end of harness (or combined/merged looms) that supplies the three 4mm Red leads to that post. I believe the wire you are looking for would be in these bundles that run along the upper passenger side engine room from the post back to the CEP.

I do not believe it would be at the 14 pin for any MY. My diagram shows a direct connection from Q3 to the device, I believe all 928's would be hot directly to the motor...the dog's gotta hunt...logically it should be near the device and close by harnesses. Any low voltage induction trace you can do isolating the wire off Q3 would be nice.

Pretty sure all have the protection of high temp and pressure switches between power and the compressor clutch.

http://forums.pelicanparts.com/uploa...1389275924.jpg
Low Pressure Dryer Switch ( Near or next to the Dryer front of Radiator Area
http://forums.pelicanparts.com/uploa...1389276037.jpg
Link to this Info :
THE 928 HVAC SYSTEM
starting with the 1980 year type , and yes there were two versions , version one= Non Climate Control( can be recognized by NO temp sensor vent in center console(upper section) . Version two= Climate control (has the temp sensor )one inside as mentioned and one positioned outside in the left front guard area. Also for the 1980 to 1989 is the large and highly respected N/D A/C compressor , and from 1980 to 1986 a much larger A/C condenser electric fan , the non climate control version was deleted around the time the 4.5 928 was discontinued .

As is often the case with a 928, the most common problem with the electric cooling fan seems to be bad connections on the fuse or a bad relay. The fan motor, coolant temperature switch, refrigerant temperature switch, and wire harness can all fail, but these failures are much less common than fuse and relay problems.
************************************************** ********************************************
Another problem with the electric cooling fan is that the refrigerant temperature switch seems to be ineffective. It would be better if the electric fan ran any time that the A/C compressor was operating. One way to accomplish this would be to install a heavy-duty in-line relay, triggered by the A/C compressor signal, to operate both the compressor clutch and the cooling fan. A diode should be used at the fan, to prevent triggering the compressor when the temperature switches operate the fan.
************************************************
The electric cooling fan may not run as often as you expect. On cars up thru ‘86, the fan does not automatically run when you turn the A/C on. It only runs when the coolant is very hot or when the Refrigerant temperature switch is triggered.

To check the electric cooling fan, turn the ignition switch on, pull the connector from the refrigerant temperature switch (located on the stem sticking up from the receiver/dryer between the radiator and the bumper), and jumper between the contacts in the wire harness. The fan should run.

If the fan does not run, replace the connector, and pull the cooling fan relay (not the blower relay). Jumper between terminal 30 and 87 in the relay socket - the fan should run. If not, check for 12 vdc at the fan motor connector. If there is 12 vdc at the fan connector and the ground is good, but the motor does not run, the fan motor is probably bad.
Note from Aluminum :
I am Not sure where the location of the evaporator temperature sensor is but under the dash I think on the Drivers side

So First Step at this Point well be to test for Current at the Low Pressure Dryer Switch
Also to Test for Connectivity to see it that's indeed the correct wire coming from Q3 to the This Dryer Switch .
At This Point if I Have Current at this Switch when the AC Button is engaged I should be able
to Power the Compressor from this switch
Since I Can't find the Wire to Hook to the Compressor coming from the Switch Yet I May have to Run a wire from the same ( Low Pressure Dryer ) Switch.
However now that I Know of this switch Perhaps I can trace down the wire Finally . My Guess is that it is Broken off just inside of some Wire Loom very Near the Hot Post of the 14 Pin Connector > Pass side Front next to Cam Cover on Fender well
Another BIG Issue is the Type of Oil in the Compressor .
Since the Car sat for some 15 Years certainly the " Type " of Oil in the Compressor most likely is not compatible with the Current types of Refrigerant .
IE: the Mineral Oil well not work and upon running the Compressor with the Old Non compatible Oil the Compressor well be Toast in short order .
Toast anyone ?

Yes you are now on the right track. Lets stop calling an AC Compressor a Cooling Motor - someone is not helping here - I think they were answering a quite different question on the cooling fan? (nothing on your 928 is called a 'cooling motor' you have a Compressor & a Cooling fan which are of course very different things).

Power to your AC head unit also supplies the AC Compressor Clutch - This power is supplied via Fuse #9. Power enters the AC head unit on its pins 4R & 5R.

A switch in the head unit slider connects power to the evaporator freeze switch (located in the bulkhead area under the cowl - on the Air plenum). The slider switch output exits the AC Head unit on its pin 9L as a Violet/Yellow wire and travels through a single pin connector to the Freeze switch. (need 12V+ on both switch pins for AC active).

From the Freeze switch it is connected (another Violet/Yellow wire) to the Central Electric (fuse/relay) panel on pin J2 (on bottom connectors) from there is just connects to pin Q2 (no other internal connections) and exits as a Black wire (in a loom) to the low pressure switch mounted near the AC dryer. This loom goes through the firewall grommet and runs under the (LHD) passenger fender lip to the front.

From the low pressure switch (open when refrigerant pressure is too low) a black wire goes back to the 14 pin connector (also via the loom) on Pin 9 and carries on as black wire (now in the engine loom) to a single pin connector where it splits to two black wires; one to the Compressor Clutch and one to the Supplementary Air valve (for AC active idle compensation). The final leg to the compressor should have another single pin connector where it switches to a red wire (the final leg to the Supplementary air valve stays a black wire). These two single pin connectors should be near the loom & near the AC compressor...they may have been ripped off... if so you can run a new line direct from the 14 pin connector to the AC compressor clutch(its quite close) - however you must also find & connect up the supplementary air valve or you may stall at idle with the AC on - you can find that later of course...

Central Electric Pin Q3 on your car is not related to the AC clutch - only the Cooling fan. You do need this to operate correctly for AC (and engine cooling), but its quite independent. If your cooling fan works normally in driving - then don't worry about it for now - until you get the AC compressor working.

Alan

About the Compressor Oil after Wiring the Compressor to Run
http://forums.pelicanparts.com/uploa...1389280112.jpg

Alan is the expert in our electronics.

My apologies for referencing Cooloing Motor...this device is stated/named in the 1979 Porsche 928 current flow diagram as are all the dependent devices. Of course not having a dictionary to translate the terms within the diagram can cause confusion.

I have said you need your MY diagrams, for true reference info which can then be used to determine what is still original and not.

Aluminum...nice detailed info pasted in...where does it originate?

Thanks Everyone for the help :
The Bits and Pieces I Got that Turned into Detailed Help of the right sort has Helped Me enough to Know how to search the net and get additional Help.
However Now It's all right here from You Great Members .
Your all Smart and Professional and very friendly
PHOTO OF supplementary air valve ( From the net not my Car )
http://forums.pelicanparts.com/uploa...1389317772.jpg
Today I Used Your Help and Jumped the Low Pressure Dryer Switch after checking that it
(1) Indeed Had Power with the Key on and the AC Switch Engaged
(2) Switch was Closed and i jumped it
(3) This Allowed me to Check for Power at the supplementary air valve
3A was no Power until I Jumped the Low pressure Dryer Switch
(4) Upon Realizing that the Power for the AC Compressor Must Come from this same switch since I had no wire going to the AC Compressor I Soldered in a new Lead
with 2 Wires . 1 to the Compressor and 1 to the supplementary air valve
.......
At the AC Compressor was 3 wires 2 going in to it and 1 coming out RED in color that changed to Black after going through a Factory wiring Junction ** However this wire ended after about 5 Inches Cut or Broken off .
TESTING :
Simple Start the Car and Engage the AC Button
RESULT : AC Compressor now spins and stops when AC Button is disengaged
So The Basic Function is working now
Of Course I expect the Refrigerant is low after 15 years of non use humm
I Hope I can find some Compatible Refrigerant with the Oil in the Compressor so I don;t mess that up.
ABOUT the supplementary air valve in case someone was wondering that's a Valve to speed up the Idle when the AC is on

Evacuate, leak check, purge, replace dryer, hold a hard vacuum for a few hours, refill. R12 if you can get it works best.

Thanks I doubt I can get R12 ?
ABOUT THE DRYER
Just what Exactly goes wrong with the Dryer anyway ? I can find no info on the net so far on that > Just says replace it < But not why ? or what goes wrong with it
Does it get Plugged up with something ?
I understand you can get a aftermarket one for much less other then the original one . Also that they work just fine .
Here are some comments from Pelican :
Comments: I am having question about the a/c of porsche cayenne.when do we need to replaced the dryer cartridge and what is the symptom or reason to replaced it.
March 15, 2012
Followup from the Pelican Staff: If there is a leak in the system or a restriction, you would replace it. - Nick at Pelican Parts
Comments: I have a 1985 911 cabriolet. I took the belt off the compressor 10+ years ago because the a/c never cooled very well and i got tired of replacing Freon. Will there be a problem if I put a belt on and recharge the system at this late date?
August 8, 2011
Followup from the Pelican Staff: Maybe. i would check if the compressor spins freely. Sometimes compressors will seize when not used. At the minimum, check it for leaks and replace the receiver/dryer. - Nick at Pelican Parts
Comments: I have an 87 944S, and would like to get some A/C going for the hot summer, but the system only takes R12 and that is not available in stores... rumors have it that some places may sell it but will charge an arm and a leg due to the environmental controls. Anyhow, I have seen the R134a conversion kit which adds some sort of valve. Is this something I could use and do myself? You mentioned earlier that 'extensive' changes are required, but I wonder if I can get more detail. Also, I don't know how long it has been not working, so could other things be wrong with it clutch?. The fan blower works, heat works great. Thanks!
June 17, 2011
Followup from the Pelican Staff: I would have the system leak checked. Repair the leaks. Then replace the receiver/dryer and retrofit to R134. You should be OK. - Nick at Pelican Parts

Humm I stand Corrected You Can buy R12 I see lots of it on CL runs about $20 Per Can
That's good advice you gave me " Danglerb "
I like the idea of holding a vacuum the longer the better > what about 27 inches ? or so
************************************************** *********************
Whats evolved with changing the seals ? Must not be all that many seals are their Anyone ?

If the dryer has been exposed to an open system (e.g. leaking) then its been exposed to a lot of moisture (in ambient air)... this means it's already accumulated all the moisture it possibly can and is now exhausted... You need a new one - don't even think about it...

Alan

" Gotcha on the Dryer "
Thanks Alan For all the Expert Electrical Help / Advice
I Must Admit I was a Bit Surprised the first time Viewed the Electrical Panel
Fuses / Relays and all the Plugins / Upon Flipping the Panel over and seeing the Mass of wires twisting every which way I had to Laugh a bit .
Having owned a Ton of Cars this was a " Experience " to use a word .
once I get the Air up and running I do like the Idea of the Cooling Fan running all the Time the AC is on .
As I also have a house in Las Vegas where it is Very Hot a lot of the year. However I well give the Factory System the First Shot

If you live in Vegas the mod to have the fan on whenever the AC is on is highly recommended - I think you will need it. If you do ever convert to R134a you will absolutly need it or you may damage the system from overpressure.

You have to remember that when the 928 was introduced cars looked a lot different and a single removable panel modular/removable element fuse & relay panel like this was quite a marvel - like something out of Star Trek.

Here is a picture of what a '77 Camaro/Chevelle fuse box looked like for comparison:

http://www.chevelles.com/showroom/da...e_fuse_box.jpg

People look at the mass of grey wires on the back and think its bad. Actually making them as short and direct as possible looks crappy but is a good thing. Keeping it simply wired gave Porsche lots of flexibility to do YTY changes - and they did. Porsche didn't design this for owners to mess with - so they just used grey wires everywhere - this was a very expensive luxury car - if you could afford the car you could afford to take it to a factory trained technician... (so they thought - and it was probably true for the first 5-10 years) so a very reasonable choice.

The good news for us is that though daunting and intimidating - its all fixable - the modularity helps, you can change any connection, replace any terminal, swap out any fuse block or fuse terminal, any relay socket or any plug connector. Also excellent is that you can easily take the whole thing out and do any work needed in comfort in a chair at a table rather than laying upside down crammed into a footwell with your back in agony.

There is also expansion room built in for additional relays, fuses and connectors (there is always even a whole spare unused plug available)... Its actually great. A modern VW fuse panel with any issues is a throw away & replace the whole thing deal - and has no expansion opportunities at all...

So to me it was and mostly still is a great design - the biggest issue is that they are all now about 20-35 years old - so they are more brittle & generally more oxidized - so we need to be careful.

Now placing it right under the bulkhead penetration for the blower motor recirculator box with no drip protection may not have been the smartest move...

Alan

Well I am, Learning Electrical much better then Ever Before ! It seems easy for me when you have a Expert Guide Thanks Alan and others . My Hands on is much better then reading the Electrical Schematics from a manual not that would be impossible to perhaps someday surmount .
Yes ! My Own Take on the 1980 Yr Model is that in fact the Wiring itself is just fine with the exception of : The Printed Circuits ( Dash Pod Area ) is weak at the Hookup Points . The Connections from Relays to Wiring Connections ( Copper ) Corrosion /. then Rust .
( if your very careful you can avoid damage to the Printed circuit > Watch the hook up points )
I am in agreement with Alan the the Basic Panel Set up is indeed well done for Its time with room for expansion and the fact that "indeed the Panel is repairable when damaged " That's a Huge plus side
The Panel Needs Maintenance that's all 30 Min's a Year should do wonders .
A Tip on Relays You can many times remove 1 Relay to get to the Next Relay and so to the next one and so on . When one is removed it makes it more possible to insert a Pry Tool to Giggle the next relay Helping Its removal .
So Once My Compressor Wiring ( Now in order and Indeed working ) is behind me and the New Dryer in Hand with some R12 ( about 3 or 4 Cans )
I can try to change out all the Seals and inspect the Compressor Pulley for signs of oil from that seal IE " freon Leakage "
I can Move forward and try to find a AC Expert to Leak Test the system and do a a vacuum Test on it for about a hour or longer .
This chart seems to be about right
R12

1978-1979
R12, 950 grams or 33.5 ounces

1980 - June 1988
Revised Factory recommendation,

Single evaporator systems R12, 1050 grams or 37 ounces
Dual evaporator systems R12, 1200 grams or 42.3 ounces

July 1988 - 1992
Single evaporator systems R12, 950 grams or 37 ounces
Dual evaporator systems R12, 1150 grams or 40.5 ounces

*before you attempt to charge using refrigerant weights
stated above, always check in the engine compartment for
the factory R12 sticker, and verify the charge using an
R12 Pressures and Temperatures Chart

R134a

1978-1982
R134a, estimated 807 grams or 28.5 ounces

1983-1992
as per TB, 9501, 12/19/1995

Single evaporator systems R134a, 860 grams or 30 ounces
Dual evaporator systems R134a, 1030 grams or 36 ounces

1993 onward
Original Factory recommendation

Single evaporator systems R134a, 860 grams or 30 ounces
Dual evaporator systems R134a, 1050 grams or 37 ounces

*before you attempt to charge using refrigerant weights
stated above, always check in the engine compartment for
the factory R12 sticker, or an R134a retrofit sticker,
and verify the charge using an R134a Pressures and Temperatures Chart

There is another thread active now... I wouldn't remove relays (or anything) unless you have to - e.g. focus on known/suspected issues not just routine PM - too much risk of damage & degradation to do that (exception is: do routinely clean the ground points). You may need a lot of work to catch up the panel now - but don't turn it into an annual ritual - just aim to keep it all dry & protected.

There are some other issues with the panel: Porsche didn't always put all the fuses there... (tucking the 2 central lock fuses behind the panel was weird). The power feeders to the panel are done wrongly and are not fused - its amazing there aren't more issues due to that.

Alan

I Could not agree MORE :
I Also read this
"
Another problem with the electric cooling fan is that the refrigerant temperature switch seems to be ineffective. It would be better if the electric fan ran any time that the A/C compressor was operating. One way to accomplish this would be to install a heavy-duty in-line relay, triggered by the A/C compressor signal, to operate both the compressor clutch and the cooling fan. A diode should be used at the fan, to prevent triggering the compressor when the temperature switches operate the fan.
************************************************
However Just How is the best way to do this ?
Let's see it says install a
(1) in line triggered Relay Question ? What sort of relay would that be ?
(1a.) just what size wire and from where should I run it to this relay ?
(2) Triggered by the AC Compressor signal . Question that's the Hot wire to the Compressor yes ? But that wire ? does it trigger also the cooling fan ?
(3) Now this Diode ? Question what sort of Diode ? Type ? / Model / Link to Part ?
(3a) is this correct in a 1980 Model YR ? the signal wire to the AC / Idle control Signal also signals the Cooling Fan ?
I thought the Cooling Fan was controlled by some Temperature Control . The Guy Mentions this
"prevent triggering the compressor when the temperature switches operate the fan."
Alan any Directions you can give to set this up would be great .
I Understand the Diode Idea But have no Idea what sort of Diode they are talking
Now the Relay Just what sort of Relay would be good for this ? Not familiar with a In Line Relay Types
So This Diode allows the Power signal to go to the Fan but Not back from the Fan ? or do I have this all wrong ?

Yes you use the compressor clutch activation wire to activate the relay. An in-line relay is just a normal automotive relay used in close proximity - placed in the engine compartment in this case. It also implies a serial connection - but that makes no sense here - miss-used term.

I'd suggest you use a weather sealed 30A SPST or SPDT relay like a hella:

http://static.summitracing.com/globa...7794321_xl.jpg

http://static.summitracing.com/globa...-H84709001.jpg

Easy to mount and use - Screw the case to something and wire using the pigtail - use 12 AWG wire.

See if pelican has them.

You can just connect this relay in parallel with the exisiting fan relay to drive the fan (via terminals 30 & 87) power it from the jump post (on 30) and connect to the fan motor power terminal directly (on 87).

Connect the coil to the compressor clutch wire (86) and also to the starter solenoid signal (85) connect this to pin 14 (Yellow wire) on the 14 Pin connector @ jump post. You can use 16AWG wire for just these 2 connections.

You don't need a diode unless you plan to use only the existing relay.

Operation: fan works as normal - except it also comes on whenever the compressor is on (this is only active when ignition is on). This also turns the fan off when the starter activated - this is what you need.

There is a different modification to protect the small AC clutch relay in the head unit in later models - you don't have this - you have a switch in the head unit for the AC Clutch relay - so no need.

Alan

Sound's Great Yes a Hella I remember that Hella Brand is a good one
I shall Wait until I get the Air Con activated first I Guess so that I can see if the Cooling Fan is working at all by the Normal Means I suspect the temperature Control cuts it in and Out .
I don't know yet just where the Temperature Control is, have not looked for it yet
I Have the Air Con Relay Jumped just now as that Relay was rusty and with some broken Prongs. Bought a Small Size Car Trailer and shall Haul that Porsche to Vegas soon rather then drive it as I need the PU Truck anyway. The Gas Cost saved well pay for 1/2 of the Trailer $400
In Fact I Picked up a Handful of Relays in Santa Rosa all original OEM along with a Idle Control Valve also OEM the one that speeds up the Idle when the AC is on a Vacuum Valve with Electoral Innards . Powered also by the Compressor How Wire. Just happened to see some Very Old Auto wrecker Yard and walked in and asked if the Had a 928 ? Sure enough a 84S in fact I Got the Mint Door Panels ( Black in fact ) / Glove Box / Relays/ Idle Control Valve . All the Attaching Hardware as the Guy Larry the owner let me pull everything my self i n fact and Evan Left me to do it with my Wife all alone with no over the shoulder eyeballs lol
I well get the Inflatable Spare Tire / door Jam 928 cover / and the Rugs when I pass through again in a few Days to Vegas as all that stuff looks to be in good condition . Darn the Windshield is Cracked however . He was Amazed I pulled the Parts in about 15 Min's and sold everything for a Very Low Price $100
Thanks for all the Electrical Guidance and support I really want to Hook up the Fan to run with the Air Con on all the Time . This well Happen and I had a feeling you would have a Simpler Solution Then I had Previously Read of

Sounds like you did well at the scrap yard - nice find (and very good prices). 20th street here in Phoenix has lots of 928's - but that means they know what stuff is worth... (but its usually in pretty good condition). The owner - (also Larry) drives a GTS - so he really knows....

If the car is running you can do this mod even before the AC is fixed and you should be able to tell that the AC head unit controls the fan correctly, no need for the AC clutch/Aux air valve to even be connected for this to work.

Alan

Car is indeed Running and seems to run well so far but the proof is in the Pudding lol
I shall Register and get Re- Plate it soon perhaps tomorrow and take it out for a Better run .
I Jumped the Relay because I wanted to test the AC Compressor was indeed working when I Pushed the AC Control Button. Yes it Kicks in but I only let it run a few seconds .
( First I turned the AC Clutch by Hand and it was Very Stiff at first but loosened right up after a few turns to a lighter drag )
" Idle Control Valve " The Latter 1984 Type rather then 1980 Type is much improved .
At the Bottom of the Idle Control Valves the Hook up point for the 2 wires
The Early 1980 Type has a exposed Reddish Brown Color Bakelite circuit board at the Bottom of the Switch with the 2 Prongs sticking out for the Wire Hook up. When Pulling the Wire Clips apart the Bakelite just broke all apart and left 1 single wire per hook up sticking out of what was left of the bottom of the switch lol ( Not worth a try to repair I thought )
The 1984 Type is Solid Metal at the Bottom so when you pull the wire Hook up they can't just brake all apart .
Not sure what Year they Changed that ?
I Bought the 1980 928 although the price was right because 1980 Has no Air Pump !
and the associated smog equipment and also because the wiring looked Good except for corrosion at Hook up Points .
Yes Back on topic :
I was thinking I could hook up the Air Con Fan Now and Perhaps I well . What I was really trying to achieve was to see if the Temperature control for the switch works at all ?
Now I am not sure if that's what controls the Cooling Fan to go on and off or not but was Just thinking it must be something like that ?
On the other Hand a Moot point if I wire it all to work when the AC Compressor is on and off when it is off so who cares I guess .
For me to resurrect a Car is as close as I well get to Build a Car at this point lol

Stock configuration is that either the coolant temperature switch or the refrigerant temperature switch can trigger the fans to come on. Seems there are issues with the refrigerant temperature switch working well. Its better if the fan is always on with AC - if the temperature switch is working properly it won't be off much of the time anyway...

Its impossible to test the refrigerant temp switch without a working AC and even with a working AC its a very indirect and ambiguous test - if you have dual system pressure meters on the AC low/high you could tell - otherwise it's a best guess.

Alan

Alan :
Drove the Car up the Coast and back some miles and it runs very cool . The Radiator is Newish and the Motor feels cool under the hood after driving the gauge only picks up to about 1/4 of the way up. I have not replaced the Cooling fan relay yet so don't have a clew about the electric Fan cutting in premature or not . I shall proceed with the Inline Relay Idea for the Fan related to the AC Operation . Not sure if I " like the Made to Bleed " Air Conditioning Hoses that require more Freon then normal as it has a planned leaks out . Humm Perhaps a Solid Metal Hoses would be better
The 1980 run's great by the way i was Very Impressed with the handling but the Power after sitting all those years is overwhelming , comparable to my 3.6 C4 911 somewhat
Thanks again for the great help

If you only get 1/4 way up the temp gauge after a long run something is up - maybe the gauge/sensor or maybe the fans are in fact on all the time (check?).

You should be above 1/2 closer to 3/4 on the temp guage.

Alan

Perhaps the Thermostat is missing ? However the way the Radiator ( a New one ) filled when I flushed it and installed New Anti Freeze gave all the signs of having a Thermostat
IE: Needed more Water after the Motor running warmed up some 2 or 3 times .
Remember the early 1980 Cars with little almost no Smog (Like no Air Pump) require much less heat to run smooth. As A former Smog Inspector I Know as they piled more and more smog Cra* on was to > See Below <
the best way to make it still run smooth at low speeds and Idle was to the heat the engine . This of course shortens the life of the engine considerably
My 97 F250 Gas Model Truck ran so hot i jerked the 195 Thermostat and Installed a 160 Thermostat now it runs just hot enough for reasonable Heater conditions.
I also jacked up the Ing Timing and my Fuel Millage improved as well as the running performance. Those Ford Trucks have a 5 Degree retarded Camshaft instal also as a smog Issue and run poorly related to Performance.
I well sometime get a Cooling Fan Relay 928 615 111 00 78 to 81 YM
then I can Test the workings of this Fan coming on or not .
When I also get a Gasket Perhaps I well Pull the Thermostat housing and have a look
I see Can's of R12 for sale in San Diego humm perhaps if someone shipped it to me it might blow ?
http://sandiego.craigslist.org/csd/pts/4283594879.html

If the thermostat is missing on a 928 you will likely overheat (it works differently than most cars) - so it isnt that.

A lower temp thermostat is not a good idea on a 928 - it wants to run rather warm.. its a Porsche thing... (remember the air/oil cooled legacy = hot engines).

A lower temp thermostat helps nothing - if your max cooling capacity is insufficent you will overheat regardless of the thermostat temp (you will just run less efficiently most of the time) just stick with stock temps.

Alan

Thanks for all the help everyone with my Air Condition Wiring / Controls . Was a great Help to get it set up for Charging and such . Saved me a lot of time .
Not being a Porsche 928 mechanic Per say.
As For my Car running Cool I like that Way as it does not have a bunch of Smog Junk the later Cars Have. Like no air Pump and a bunch of retarded Parts
Their is nothing wrong with the way Its running Temperature wise it runs just like Most cars I have owned . Performs just fine and most certainly does not need to run hot.
Water Cooled Cars do not like Heat Long term in my Option . However if you have a model with a lot of Smog then you don't have a lot of choice do you
they don't like to Idle with all that Smog so they Heated them up
Your welcome to delete My Posts if you don't like them I could really care less.
After working for many Dealers for many Years I Think I have a handle on things Evan tho I am not a Factory Trained Porsche 928 Mechanic .
The End lol

"Your welcome to delete My Posts if you don't like them I could really care less."


Why would anyone want to do that, this is a very educational topic, lots of good questions and info here.
Good job fixing your ac.

Who suggested deleting posts here? what is this all about...?

Alan