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The cooling fans are not operating on my 1986 944, so I tried some troubleshooting with the help of Clark's Garage. I did the test he suggested (jumpered the electrical connector for the thermofan switch) and the fans never came on at low or high speed. I popped open the relay and noticed this brown buildup (please see pic). Just wondering if anyone has seen this before and if it might indicate that the relay is shot? I used a loupe to examine for cracks in the solder joints and noticed there are a couple. I was going to try to solder it, but just thought I would try to get some input about the brown build up.
I also jumpered the fan motors, to make sure the fans are working and both of them came on, so I am thinking it might be the relay.
Any input would be appreciated, thank you!
How do your wires look at the resistors? There those two big round ceramic parts mounted on a breaker under the passenger wiper below the front windshield. Those are the resistors for each fan. I just got done running new wire to all four of the connections from the power distribution block.
Thanks PaulD_944S2 and Humboldtgrin for the helpful info!
I resoldered the cracks and joints on the relay last weekend and both fans only worked in high speed.
Today, I checked out the resistors and wiggled the wires around a little. Now, only the driver's side fan works when jumped in low speed. The driver's side fan only works in high speed when jumped, but only when the ignition key turned "on". But, now when the AC is turned on, both fans work.
The wires felt a little brittle and look a little beat up and corroded on the resistors, so I'll have to look into those more. (mine are located behind the glove box, I have an automatic)
My 85.5 five speed has the fan resistors in the same location inside. They must have moved them on later 86 models because my other 86 has them outside the cab under the windshield as do my three 87’s and 89. I found that all of them have the same wire corrosion issue. You might want to replace the wire with a 10awg wire rather then the factory 12awg wire. And you may want to pull your Power Distribution Block and clean it. You can inspect your wires that plug into it while your at it. I have a write up on the 944 turbo forum full of photos to help and plenty of info on how to remove and rebuild the Power Distribution Block. I have rebuilt seven so far, it’s pretty easy. https://rennlist.com/forums/944-turb...-cleaning.html
07-07-2018, 07:56 AM
1986 944 Cooler Fan Relay Question
