Electrical issues - 944 "masters" needed..

[yieldsign2]

OK. I found I do have a bad alternator, so I am buying a new one but even with the alternator not connected I am still having issues. If it is somehow that the alternator needs to be hooked up , let me know, but I don't see any reason. It was doing this even with the bad alternator. alarm box is removes and jumpered the way described at clarks garage.


I just got done a rebuild (engine out) and I installed iceshark battery cables, and removed the stock alarm.. Really crazy things are going on.

If I hook up teh battery cables to the battery everything is fine. 12 volts constant to pin 86 on the DME and ignition relays. 0 volts to pin 85, i believe it was.

Pin 85 should get 12 volts when the key is turned to the on position, energizing relays and whatnot. Key on - 12 volts comes to pin 85 as expected, fuel pump turns on.

Turn key off - RELAYS STAY ENERGIZED - fuel pump continues to run - ! light is on on the dash, even with key out.. 4 volts at pin 85 (this is where the problem is, I think?). The 4 volts is just enough to keep the relays energized, and from tripping off. a VERY LIGHT flick of any relay trips it off, ! light goes off, and everything appears normal. Not sure if 4 volts is still coming from the ignition switch or to the power of teh alarm relay area, I'll have to check that again.

It is clearly the 4 volts holding the relays open because it is very easy to flick a relay and get it to trip off - 4 volts is barely holding them energized.


Even more whacked....

Passenger headlight only works on normal beam. Brights shut the passenger headlight off.
Headlight pins voltage. - Ground is good ground, upper pin (yellow wire) gets 12 volts on brights (maybe vice versa but regardless).
last pin (white wire) - 12 volts on normal lights on.

I believe it is the yellow wire, where you see the 12 volts with teh brights on (or normal lights on if i have it backwards).


I've pulled each relay one by one, and it acts the same. So it's nto a relay I don't think. I've tried 2 DME relays, 2 headlight relays, etc.

If the battery is low (from the fuel pump running) turning the key on and off will shut it off. (probably because only 2 or 3 volts is holding the relays.. just a guess).

STRANGEST THING - BOTH HEADLIGHT PLUGS TEST THE SAME VOLTAGE.. yet the passenger headlight doesn't work on high beam. I've tried multiple bulbs, including teh one from the driver side that works right.. they all don't work. IF i pull the headlight plug off just enough to test, there is no voltage where it should be.. most likely meaning somethings shorting when there is a load.

for the past two days I've checked around for voltages with a multimeter.. spent 5 hours yesterday studying circuit diagrams with my dad.. and no luck finding anything.

I've disconnected the supplemental positive from iceshark battery cables and it makes no difference so it's not that.


oh , i like i said, i have the alarm plug jumpered 1-4 and 7-8 like clarks says. I don't have the alarm parts anymore.. so that isn't an option but I have a feeling it is bigger than this...


My only possible idea I can think of - Ignition switch. Is it possible the ignition switch is leaking voltage through, or would i be the first ever to have that happen? Doesnt make much sense for the headlight issue, since that is with the key on..


help!!!!! Car runs fine... I've driven it a few miles but i can't drive it with this wiring issue draining the battery and everything.. starting to have ideas of parting this thing out, after rebuilding it for a year and a half. This sucks.

[SoCal Driver]

With out going over this point by point the most obvious mistake I see is that the fuel pump should NOT come on with just the ignition switch. The only time the fuel pump runs is during cranking and when the engine is over 400 rpm.

Me thinks your wiring is screwed. Better go back to square one and check it all over again.

[yieldsign2]

The fuel pump doesn't come on at the key on position? other cars I have do, and how would it run in the on position if the fuel pump isn't on then? what tells the fuel pump to be on over 400rpm..?

and.. more importantly... where's square one? That's kind of what I've been trying to find. :/

[bigbird944]

about the headlights, did u check the fuse? i dont see it anywhere in ur description that u checked them, just an idea, i might sound like a jackass but thats what happened to mine except low beam. if the fuse is intact, try cleaning the contacts at the fuse, mine was a little corroded due to the water issue i had with my car, once that was done the headlight worked fine, both low and high beams.

as to ur other problems, i cant help ya there, im not that much of an electrical guru

[yieldsign2]

I'll try different fuses and cleaning. i tried one different fuse and there was no difference. It's weird because the voltage is getting there.. it just goes away once the headlight is plugged in.

[SoCal Driver]

I guess "square one" is having a basic understanding of how the Bosch injection works on the 944's.

The key is the DME; the electronic brain. This takes all of the inputs from the engine and figures out how long to open the injectors and when to trigger the spark.

The two sensors on the back of the engine look at the flywheel. These are the speed and the reference. Speed counts the teeth on the starter ring and how fast they go by and reports this to the DME. Reference looks for a pin once per revolution that tells the DME where top dead center is. The speed sensor is the key component the logic for keeping the fuel pump running once the engine itself is running.

The other trigger for the fuel pump is the starter circuit. This is split off to the DME (brains) and the DME closes the fuel pump circuit in the DME/fuel pump relay while the engine is being cranked and for a half second or so after you stop cranking.

The fuel pump does not and should not be running when the engine is NOT being cranked or is NOT actually running. This is NOT like your other cars.

The Air Flow Sensor tells the DME how much air is being sucked into the engine. The flap moves a wiper on a resistor under the black plastic cover. For a detailed look at the insides go to www.frwilk.com

The engine temp sender (not to be confused with the gauge temp sender) also contributes to the DME logic in fuel delivery. There is an air temp sensor in the AFS too.

The throttle switch tells the DME that you have let off or closed the throttle. If the engine rpms are over 1200 or so the fuel injectors are shut off until the idle rpm is reached then switched back on. This is the source of the early 944 "stumble".

To refine the fuel/air ratio there is an O2 sensor in the exhaust just before the catalytic converter. Gives the F/A ratio a final tweak.

Don't confuse "other cars" with this one when messing with the wiring. You have to think German. You have to think Bosch.

[yieldsign2]

I knew most of that.. but all I can guess is that the DME is most likely to be at fault for turning the fuel pump on with the key...? Seems like kind of a weird fault for teh DME to have though.. when usually a broken solder or something would cause something to NOT actuate, or to actuate at flaky times..

this thing's screwed up... I'll be happy if I can get it back to where it was though.. The fuel pump used to run with the key like this,b ut would turn off with the key off.

[yieldsign2]

Hmm, wait a second.

With a bad speed OR reference sensor, woudl you get no spark or no fuel in either case, one case, etc? I did use the speed and reference sensors from the parts car.. but the car runs perfect so I figured they were not a culprit

[SoCal Driver]

The DME relay's first set of contacts are turned on with the ignition switch. The second set of contacts for the fuel pump do not close unless the engine is being cranked or is running. The DME does this. If your fuel pump is running with just the key on you have the wrong relay and/or the wiring is messed up.

[yieldsign2]

Well, the DME doesn't seem to power the fuel pump in any way via the wiring diagrams.. it looks like power goes from the key, to the DME relay, to the fuel pump.

The reference and speed sensors all go to the DME correct..?

so, that kind of rules out DME as being the reason for this, and points at the ignition switch right?

I would be fine pointing at the ignition switch but a random 4 volts coming through seems weird..

[SoCal Driver]

I think I see the problem.

[yieldsign2]

And what's that supposed to mean? Correct me if I'm wrong but, I take that as lil stab there? I'm sorry but my car is somewhat bastardized by the previous owner.. and I've done basically everything to cars except a rebuild and I just did that to learn, when it would've been much more efficient to sell and start over.

I just know the car ran before with pretty much this wiring and this DME and this relay, it's just sat for a year while I had teh engine out. I don't have the money to replace random parts until it's fixed, so I need to diagnose it properly.

Frankly, I don't know wiring to the greatest degree but it's something I have to learn, so I'm asking for any help. I'll figure this out on my own eventually, but I'm just prodding for some more intelligence on it. Sorry?

[944 Ecology]

OK, if you want to fix the problem, compare the wiring on your car to the wiring in the factory wiring diagram. Change everything on the car to match the wiring diagram. Keep doing this until there are no differences.

When that is done, your car will work as designed.

On the other hand, if you just want to continue the cobbled work of the previous owner, I guess that you're on your own. Keep good notes to provide to the next owner of all the discrepencies between your car and the ideal car.

[Granite 944]

Originally posted by 944 Ecology
OK, .................................................. .................................................. ........On the other hand, if you just want to continue the cobbled work of the previous owner, I guess that you're on your own. Keep good notes to provide to the next owner of all the discrepencies between your car and the ideal car.

WOW!

WORDS...........NEVER...........be so TRUE!

I don't care.... about WHY. "no money, cheap, no experience, or whatever"................. JUST TRUE.

Butt..........It DOES, require MUCHO research and such to get it straightened out yourself...........as a "shade tree" type mechanic? After all, these ARE..........older cars.

And those that do NOT do this, and, just depend on forums like this, .........and just go on without getting and having FSM manuals, TSB's or tons of professional, or on the job/or hard knocks experience, are just gonna spend tons of money, and learn the "hard knocks way". Sad, huh. Its all out there.....we just need to point them in the right direction to find it.........IF they haven't figured it out on their own........right? (Like.........I haven't done the "hard knocks, myself?....and STILL do).

Love to see more people get the reference data to support them, besides just these kind of forums...........wouldn't you?

'taint , really, that hard to comprehend, IMO. IF, your gonna play.........your gonna PAY. True? or False?

There ARE.......plenty of "troubleshooting" procedures out there to follow at Clark's, and others. BUTT...........they MUST be followed to a "T" in order to logically KNOW if and where, the problem is. (that MAY include having to spend money on the neccessarry tools to do such!). Maybe thats why so MANY people take their cars in, to be worked on, and diagnosed? Maybe they.........are the smart ones? OK........its the LOVE.......of the car.........I know! I'm screwed!

BUTT!....ALSO.............to many things, being done at ONCE..........CAN........and WILL..........make it MUCH more challenging. Especially.......IF the car was NOT per stock spec. when started on.

So..........starting at a logical beginning point (who evers logic that may be), would be the best route, and follow thru from there.......point, by point? Seems true to me.

Just as a side note. I'm STILL trying to get a FULL, BASIC understanding of ALL these car's systems/functions......myself!

KUDOS! to those that already HAVE it!!

GOOD LUCK! You WILL get thru it!!

[yieldsign2]

Yeah.. everything you said is right Granite.

I think you hit it right on the money, and basically what you said is what I have followed. I clearly DID A LOT of research prior to succombing to posting a thread here.. did a lot of diagnosis on my own, and am not looking for someone to fix this problem for me as unless someone fixed teh exact same problem, they aren't going to know. I am just posting so that any little bits of knowledge from other people, I can collect with mine and possibly come closer to the answer. It's just going to take a lot of following wiring diagrams, and possibly never having it work 100 percent correctly, but if the car runs, and everything turns off when I turn off the key, I can drive it.

I just think the stereotype of poor kids getting a 944 that is over their heads and holding it together with string until it dies gets in teh way sometimes.. because that is NOT WHAT I AM. If the car was over my head, I would get rid of it, since I have a land rover (or 3) and I even bought a volvo to be a failsafe car when these HOBBY cars are dead. I don't have much money.. but that's why I've made this a 1.5 year project to rebuild the engine.. I wait until I have the money to do it right. That doesn't mean I did every possible while you are in tehre thing, but I didn't cobble this car together.

Hell i spent 300 dollars on my battery cables.

When my new alternator comes in tomorrow that i ordered today for 200 bucks, i'll probably be able to drive the car. As long as I run the car, the fuel pump turns off. I just can't turn the key to on then off without running it, which isn't a big deal as long as I know. I'll continue to look for the answer to this mystery, but as long as there arent more problems I can still enjoy a summer driving.

Oh, and clearly I have the factory service manuals.. and hanes... and PET.. and clarks, etc...

[yieldsign2]

Originally posted by 944 Ecology


On the other hand, if you just want to continue the cobbled work of the previous owner, I guess that you're on your own. Keep good notes to provide to the next owner of all the discrepencies between your car and the ideal car.

Thanks for the advice... but this is precisely why I asked the question, rather than just running a jumper wire from the driver headlight to the passenger headlight.. Im trying to save a car that was bastardized.. If I was 50 years old and saving a junk car by replacing every part with new whether it needs it or not, I wouldnt be criticized, yet when I choose to diagnose the problem before buying DMEs and ignition switches.. I get jumped all over. Its not being cheap.. its being smart.

[Granite 944]

Good luck Yeildsign2. These cars can be fun, challenging, AND enough to wanna just SHOOT 'em. You'll do fine! Hang in there!

Ya said you "have a bad altenator". How, did you conclude this?

Iceshark's kit comes with a voltage regulator. Did you install it, and test the output at the battery?

Forget the headlight thing right now. Disconnect all fuses and relays to such right now. ONE thing, at a time.

Relays. Have you tested any and all that may be suspect? HOW, did ya do this? Recheck may be required? Sometimes we miss the obvious? Look at the DME relay, and the headlight relays (old and the new ones in the kit). Check as per diagram ON the relays. For grins and giggles, checking all those relays and their connectors, wouldn't hurt ya. I love the scotchbrite, electrical spray cleaner, and dielectric grease.......here. THIS.....IS WHERE YA NEED TO PAY VERY CLOSE ATTENTION!!! You seem to have a very sticky relay on the DME or such. Just a guess mind ya. Check it though. Eliminate it. LEARN HOW to test these relays. Sometimes, we DON'T notice it the first time around, and need to test again.

Go thru the Clark's garage troubleshooting areas again! Sometimes we miss stuff.........ya know.

All connectors, contact points and such have been clean, tightend, checked and dielectric greased on re-assembly of the engine? I know........gotta ask.

You've looked at all engine grounds, cleaned and such? headlight grounds at frame rails?


Headlight problems. Get the altenator replaced/fixed. Test, when all other issues ARE resolved. Question the alarm bypass you did. It can ALL play a part in what you've got. ONE thing at a time. Bypass others, eliminate one, add the next factor. Good luck!

[yieldsign2]

Before even posting this thread, I:

Replaced headlight relay with spare
Replaced DME relay with spare
Took each relay out one by one to see if one relay affected the issue, it acted the same with each relay out, and all them out (besides DME and ignition obviously).
Used electrical cleaner on EVERY plug in teh engine bay
Removed EVERY relay, sanded EVERY contact, dielectric greased EVERY contact.
Removed all grounds I can find in the engine bay, cleaned, sanded, dielectric greased.
Lifted fuse/relay box, cleaned positive poles, sanded, greased..

Any bare wires found were electrical taped, or cut out and rewired as needed.

Still gotta tend to teh grounds under the dash under teh fuse box, and the ones in the rear of the car.

I ahve a 3rd DME relay to try as well.

It's not a sticking relay 90 percent sure though, its 4 volts leaking thorugh the system. Kind of has to be a short? Or ignition switch is the only thing I can think of...

The issue is, most of the wiring, besides battery cables, was NOT changed in this rebuild. it's just something flaky that is going on, and the issue is it could be a frayed or pinched wire pretty much anywhere, so testing is key.


Oh, and my voltage gauage was showing no charging by the alternator, and I am sure I have the alarm relay jumped correctly, so Just to be sure I brought the alternator out of the car to an Armature place 45 minutes away, and they verified as soon as it's hooked up it's trying to draw, one of the diodes is crapped out and shorting most likely.

I've also tried reinstalling stock chip , rather than the FRWILK one.

I did not do the iceshark regulator (not part of my kit) and only have the medium boat headlight kit which is just lenses and bulbs (had this before the rebuild working fine).

I'm going to buy a whole pile of new fuses tomorrow and replace every fuse when I do the alternator.

I have some wires I need to cut and extend with new wire behind teh glove box to some weird unit back there. they are all frayed and trashy.. I'm going to pick up tons of wire and more crimps and such tomorrow since I"ve ran out with this mayhem.

Fun stuff... > Anywya, with any luck the alternator will charge, and I can go flog the hell out of this thing in punishment for it fighting me the past year. Gotta play hard to work hard, but you gotta play hard if you worked hard too or it wasn't worth it.

[Granite 944]

Keep after it buddy! You'll get there!

Still.......learn........how.........to test the relays..... as a seperate unit. You could be putting one bad/iffy one in place of another, and never know it. Don't ask how I learned this myself.
Taking them out, replacing them with another "used" one, one by one, may or may NOT tell ya anything.

"Any bare wires found were electrical taped, or cut out and rewired as needed."

Ok.......this is of concern here. Did you really Find any "bare wires", and if so.........WHAT/HOW did ya handle that. (Only a concern IF your interested in long term ownership).

Considering above thought. Have ya looked at the relay box, looking for burnt and or toasted pins/connectors.........AT the relay/fuse box? I know.....you'll get there.

Forget the "crimps"!! Do it like ya mean it! Solder it, heat shrink it, forget it.........forever! Don't "crimp it" Just learn the difference between a cold solder, and a good solder job. Key....for the long run....ya know.


"Gotta play hard to work hard, but you gotta play hard if you worked hard too or it wasn't worth it."

Well........your pretty much right! Let us know if its really true in this case! Its ALL GOOD!

Note: Crappy/bad capacity batteries, or ****ty cables to and from can cause ALL kinds of havic also. ARE you SURE these are good.

P.S. By the way. I'm NO electrical, or "master" of ANYTHING. Just another nob, shade tree type mechanic.

[yieldsign2]

well the iceshark cables should be good.. considering they are like military aircraft grade...

I tend to trust banana crimps, or male/female blade crimps more than I do my soldering skills.. but I'll start practicing I guess.

When I come across wires with scraped off insulation, I usually cut out a good portion so that all corrosion is taken out, and replace with good new wire and splice in with crimps if the situation calls. I usually test continuity before taping it all up. I didn't do any of this prior to these issues though so I don't think that's what caused it.

I'll start testing relays.. I've tested voltages comign to the relays in question on the fuse box, but I can do more.

It just seems to be not a relay issue but some kind of volt leakage.. 4 volts randomly traveling around is not a cool thing!