Cadillac Repair: 1985 Sedan Deville Fans, power fuse, engine temp

Question
Tom,
I have a 85 Sedan Deville and neither one of the cooling fans will run. I hooked up the fans directly to the battery and the large one works, but the small one smokes. I replaced the main power fuse and temp sensor. I get a Cooling Fan Temp light and Check engine error. Are the fans hooked up in series or parallel? If the little one is busted, does that mean the big one won't work either?

Thanks for the expert help.

Ernie

Answer
The fans are controlled by the BCM (Body Control Module at different times.

the left fan is controlled by a temp switch that goes into the BCM and the BCM controls the fan speed via the Fan Control Module at different speeds depending upon temperature of the engine.

The right fan comes on when you use the A/C.

If your NOT using the A/C the small fan can be turned on by the BCM and Control module if the engine temp gets to high in that the larger fan needs help by the smaller fan.


You will need to contact me at:


tomcjoy@msn.com


In order for me to provide you with pictures and and electrical schematic to find and fix your problem since this board does not allow sending pictures.

PLEASE include your original question(s) and the MAKE-MODEL-YEAR and ENGINE SIZE of your vehicle when you contact me.

PLEASE tell me if you do your own repairs and or your skill level of auto repair. This is VERY VERY important if I am to be able to help you repair your own vehicle or have to take it into the shop for repairs.



Tom