Cooling system fan

jskahler

Registered User
My cooling system fan retired on my 1990 SC. The motor would not turn leading me to replace the motor. When inspecting the motor, the female three-pin connector showed signs of high heat (I assume from the motor bearing seizing and 12VDC being applied to the low and/or high speed setting caused the deformation of the pin-ins in the connector). Upon replacement of the fan motor, I started the engine, engaged the A/C system and the fan did not operate. I then allowed the engine to obtain normal operating temperature to assure thermostat operation and continued to allow the engine coolant temperature to rise. The fan did not engage at high temperature. I have inspected the wiring from the male fan motor electrical connector to the first harness break-out and find no damage to the wiring insulation. My code reader shows no codes. What next, check IRCM relays?
 
I would Check the relays, but also check the distribution box under the hood that has fuses in it and make sure that none are blown
 
There is a wiring bundle that goes from the selenoid on the driver's side fenderwell that contains a set of 3 fusible links. One of these links goes to the fan. That link typically melts when the fan goes.

These fusible links are soldered to the big wire coming back from the alternator. The fan one is a 16 gauge black one. This should be replaced with correct fusible link wire and *not* regular wire! When mine burned up many years ago it also burned and messed up some other wires in the bundle. So, take a close look at the whole mess of wires.

It will probaly be soldered to a yellow wire that leads back to power the IRCM for the fan. I would check this before delving into the IRCM box.
 
That's absolutely correct. The exact same thing happened to me after replacing my fan yesterday. It only took about 6" of 16 guage fuseable link wire but I had to remove the battery & fuse box to get access & room to work on it. I was able to use a butt connector on 1 end because there was quite a bit of the old fuse left and I was able to remove and reused the original plug connector going to the yellow wire.
 
Thank you

Fuseable link was the answer. It hid well from me as the insulation wasn't burnt off. I guess my Voltmeter reading of .5VDC wasn't a mirage. FYI, my wire (fuseable link) running from the alternator harness through the single connector to the "yellow" wire (that feeds the relay box) is 12 gauge. System checks OK. THANK YOU for the accurate diagnosis doctors, you saved me a headache.
 
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