Mooll944

Hi, im really hoping you guys can help me. pleaseee. any suggestions welcome. Im sure you guys are aware of the bad / frayed wires at the cooling fan resistors. well, mine are bad up the WHOLE harness. i followed them all the way from under glovebox to the drivers side. most likely since one of my fans was frozen, it caused the wires to have too much current or something like that and fried them. they literally pull apart in my hand. it's not just the ends like everyone else. I really have no idea what to do. replacing the whole wiring harness is out of the question. Is it possible to maybe add an aftermarket electric fan? doing anything with the existing trashed wiring is a fire hazard for sure. I thought about cutting the factory electric fan connectors and running new wires from them to the factory resistors, but i dont even know if that's how it works. THANK YOU!!

Mooll944

Can i put in an aftermarket fan and maybe just have it run all the time? i went this far saving this car already from the pile of poo it once was, please help!! thanks

Mooll944

I think my only option is to add an aftermarket fan and have it run all the time and just bypass all the factory stuff. i could add a switch in the interior that turns the fan on and off?

931guru

Sure, you could do that... Make sure that the wiring and the switch can handle the 15 or 20 amps, that the circuit is fused, and that the fan is pulling air into the engine compartment. Real race cars do that all the time. (The reason for the thermoswitch, the resistors and the relay is to make the running of the fans automatic and the driver usually ignorant of their operation.)

Mooll944

Ok cool, so i guess this is thev only way to do things. i should probably pull the fan relay, right? any idea on how to go about wiring an aftermarket fan up, and where to get one? thanks

Millermatic

My wires were pretty bad. Not quite to the length of yours. I replaced them. I’d try to find a way to run new wiring if it’s at all feasible for you. I appreciate this probably means taking your dash apart... but were it me... I’d be more comfortable doing that than trying to make an aftermarket fan work.

As an aside... that “thing” the wires are attracted to in your picture is a heat-sensitive metal disk. As the resistor heats up, the disk changes shape (from concave to convex. Or the opposite). That shape change completes the circuit... and your fans turn on. When the ceramic pucks cool... in pops back. FWIW... replacements are available.

Here’s my old wiring:



As another aside... if your wires are that bad... make sure your battery wires don’t look the same.

Mooll944

my battery wires look good besides some cracking on the black insulation, which i thought was normal for the age.

what happened was one of the cooling fans froze and so the wires basically got too much current or something like that and burned up. plus this was probably 15-20 years ago lmfao and the wires have just been sitting like this since then since the car was sitting in a garage, so that didn't help the wires. they are trashed going up the whole harness, at least as far as i can see from the passenger side footwell up to the drivers footwell area. no other wires look like this, they are all nice except these resistor wires.

people like you got really lucky with your wiring. mine is shot all the way up the harness. i followed the wires from the resistors to behind the heater core all the way up to the drivers side foot well and they are just as bad. i do not know where they go after this. do they go directly to the cooling fan connectors?? I would love to keep it factory and re wire it, but it is not that simple i dont think. i dont i even know where the wires go. i know there are 8 that connect to the resistors. 2 from the low speed fan i believe and 2 from the high speed fan. idk. i really think the easiest way to fix this is to wire in 2 10" cheap aftermarket amazon or ebay fans and have a switch in the interior that turns it off and on. I would try to make the aftermarket fans work on the old fan shroud. If any one has any other suggestions, let me know, because i definitely would like to keep it original, but at this point, i dont think this is possible...maybe if i can find out where the wires from the resistor end up after the drivers side foot well, i could find clean ends to splice new wires on... thanks.

I just hope the head gasket is OK if some one kept driving it like this with no fans!

Millermatic

Someone more knowledgeable than me can hopefully chime in to confirm... but I would assume the wires simply go to the fuse box (and into the fan relay) and then to the fans. I still think running new wires might under the dash might be easier. Assuming they don’t have too many splices into other wires.

Which brings me to... wiring diagrams. If you don’t have them already... track down PDFs of the wiring schematics for your car. And the factory repair manual. Both are available on the web without too much searching. I’ll admit the electrical diagrams make my head hurt whenever I look at them... but they’re really helpful. There’s a good tutorial out there on how to interpret them (specific to Porsche diagrams). I can try to find some links if you need help finding them....

There are good solutions for replacing the engine wiring harness (not cheap, but good). I’m not aware of one for the dash harness. It’s a maze.

Good luck.

Mooll944

Thanks. i have wiring diagrams i think.

GPA951s

The fans will still work with those resistors disconnected… but what happens is you only get full 12v and the fans cycle. Especially when the car is off the fans turn on and of for about 3 to 5 min after the car is shut off because the temp goes up… fans come on full blast gets below threshold .. they shut off.. heat transfers and they come back on.. on off on off …

just an FYI

Mooll944

Thanks, i didn't know that. i should still pull the fan relay though i think even though the fans been removed. those bare wires may be a fire hazard.
nice 951's!

Mooll944

I think im still gonna just wire in aftermarket fans from amazon. i believe relay number G10 is for the fans. is that correct? i want to pull it out so there is no fire hazard.

Mooll944

I've decided that i'm going to get 2 used factory fans since mine are frozen and just directly wire them up to a switch in the interior, so it'll stay some what factory.

Mooll944

i tested the fans with direct 12v power and they both worked, how ever when installed on the car i could never get them to turn on, even when i turned Ac on. maybe fuse or relay. either way, i think im just gonna wire them up to a switch and add inline fuse and relay....any one??

931guru

I would use AWG 16 or thicker wire... those fans draw a lot of current. Cheaper to use thick wire and avoid a fire.