cooling fan issue

nynor · 04-05-2004, 08:16 AM

another electrical issue:

the drivers side cooling fan comes on normally, the passenger side does not. this has been going on for two years, so i have to pay close attention to the temp in city driving during the summer. the fan is good, the ground is good, terminals are clean, the fuse is good. does the A/C relay have anything to do with the passenger side fan?
my thinking is that if there are two seperate circuits in the A/C relay for the fans, one may be bad.

right now, i have the passenger fan hooked directly to the battery, with a 20 amp fuse, and grounded to the same ground as the left fan. thus they both com on together etc. i have a universal fan relay and i am going to figure out a way to hook it up this afternoon. any thoughts?

scheistermeiste · 04-05-2004, 11:50 AM

the second one comes on when you have your a/c on or is supposed to when your car gets really hot.

nynor · 04-05-2004, 11:58 AM

exactly. but the passenger side NEVER comes on. hence, it runs hot in the summer in stop and go traffic.

any ideas? could it be the A/C relay? i know if i take the A/C relay out, neither fan will come on...

nynor · 04-05-2004, 04:29 PM

well, i have it licked, finally...

this is not the most elegant (or ideal, for that matter) solution, but..

i hooked up a universal fan relay to the fan circuitry that was working. then ran a direct, fused at 20 AMPS, line from the battery to the fan that was not working. thus, when the drivers side fan turns on, the universal fan relay switches on the other fan. works like a champ.

however, the passenger side fans runs at full speed while the drivers side fan is poking along when the engine is shut off. the up-side is that i won't have to worry about over-heating in the summer.

muhahahaha

scheistermeiste · 04-05-2004, 09:19 PM

well if its hooked up normally and you turn your a/c nob does the fan come on?

nynor · 04-06-2004, 07:50 AM

well, its not hooked up exactly normally, as it is on its own circuit. however, it does come on when the other fan comes on, so i am calling it good. i may have to take out the low temp radiator switch, now that both fans run, as it is not running hot enough.

SoCal Driver · SoCal Driver's Garage

One of the fans is supposed to run at a slow speed when the engine is hot and you shut off the key. This will stay running till the temp switch in the radiator opens up. This is to keep the hoses from bursting.

nynor · 04-06-2004, 12:01 PM

just a friendly question: are you guys reading the first post?

to reiterate, the right fan NEVER ran. the left fan ran properly. i couldn't find the problem, so i set up a seperate circuit, direct from the battery to the right fan with a fuse, which is on its own relay. voile: the right fan turns on when the left fan turns on. not the proper solution, which is to find the actual fault, but left with no choice, i will hack with the best of them. however, if anyone has suggestions as to why the right fan never worked, in two years, after replacing the relay, please let me know. also, i noticed that the A/C relay has something to do with the fans, thus, is it possible it is a fault with the A/C relay?

thanks,

d.

mambodave · 04-06-2004, 04:45 PM

stupid question, but did you check the fuse? Not the relay, the actual fuses for cooling fan 1 and 2? I overlooked one before, and it caused me hours of problems, only to remember, oh, check the fuse box. Each Fan has its own fuse.

nynor · 04-06-2004, 07:04 PM

as far as i can tell, there is only one fan fuse. it wouldn't surprise me if there is two, but it is not on the fuse chart for my vehicle, as far as i can tell. if there is a second one hidden somewhere, please let me know.

mambodave · 04-06-2004, 07:19 PM

fuse #10 and fuse #15

(on my 86)

nynor · 04-06-2004, 07:40 PM

mine is an 83... totally different. however, from the wiring diagram in the workshop manual, i may have the wrong fan relay. according to the wiring diagram there are two switched contacts. i know that mine only has one...

SoCal Driver · SoCal Driver's Garage

Since you spliced into the circuit you have one fan running at full speed and the other at slow speed when the key is turned off and the themp switch still closed.

This is wrong. You will drain the battery and not be able to start it.

Yes there are two fuses, one for each fan. Check out www.clarks-garage.com for a fuse/relay listing.

I would strongly suggest getting the electrical diagrams for the 83 off of PelicanParts and study them before you think you have a better idea on rewiring the cooling fans or any other thing.

nynor · 04-06-2004, 08:34 PM

well, haven't drained the battery yet... it only runs for a minute or so.

however, i did look up the diagrams in my shop manual (not the haynes, but the actual shop manual) which is the same as clarks garage. according to the diagram there, the relay for the A/C and the relay for fans are identical. they have TWO switched circuits, not just one. basically, they have the same diagram as indicated on the picture of this relay, part number 944-615-113-01, the A/C relay, just click on the little picture:

[URL=https://www.***************/catalog/lookup_parts.cfm?VehicleID=1263530&SubcategoryID=3604&CFID=2631430&CFToken=95594355]

i know that the fan relay i have installed has only ONE switched circuit. thus, it is missing the AB switch. is it possible that i have the wrong relay, even though everywhere says that relay is part number 141-951-253b for the fans?

idontknow · 04-06-2004, 08:35 PM

Hope it helps. On my 83, the fans are just wired in parallel.

Car on, engine cold = fans off
Car on, engine warm = fans on high
Car on, A/C on = fans high
Car off, engine warm = fans on low
Car off, engine cold = fans off

Instead of using the relay, just wire them in contact to contact. Much more simpler, and you'll lighten the front end!

nynor · 04-06-2004, 08:35 PM

also, the fuses, according to clarks, are 3 and 5. both of which i have triple checked and replaced.

nynor · 04-06-2004, 08:40 PM

ok, thats it. the damn thing has the wrong fan relay in it. according to clarks garage, the fan relays are different if the car has air conditioning. i need two of the 944-615-113-01 relays. what do you think socal?

vital-transform · 04-06-2004, 09:40 PM

don't forget that the factory lists the wrong relay part #s
see the previous posts re:cooling fans and fan relays
sounds to me like you have the wrong relay in #3 A/c location and or #1 cooling fan
I got a new A/c relay and both fans blow like ^#&$^%() with the a/c on

nynor · 04-07-2004, 05:47 AM

i think i have the wrong relay in #3. this one is part number 141-951-253b. i think it needs to be the other one. anyone else have this problem before? would someone mind checking the part numbers for relays #1 and #3? i know its a big request because they are such a pain to get to...

nynor · 04-07-2004, 06:57 AM

i think i found the problem in a previous post:

"Sounds familiar to the problem I had on my 84 944. There is one relay for both the AC and fans. No electrical diagrams show this
relay in the car. Found out from Porsche that they used this only for a short time in production and it was not documented. I replaced it and the fans work fine. Part# 944.615.113.01 cost about $33.00. Hope this points you in the right direction."

i bet this is the whole problem. undocumented, short production run, anomaly.