97 cavailer cooling problem
ace bass1
11-10-2010, 10:05 AM
Hi,all I am new to the forum. O.K. I have a 97 cavalier with 2.2 engine and the cooling fan won't kick on. I have replaced temp sensor,thermostat,fan,and relay. I also checked all wires running to the pcm everything checks out. Also the fan dose not kick on when a/c is turned on. I stumped any info. will be greatly appreciated. I have been working on cars many years and this takes the cake. THANKS!!!!!!!!!!!!:uhoh:
Blue Bowtie
11-11-2010, 10:03 PM
Welcome Aboard!
Make sure there is a good 12V source at the relay socket. Pin 30 (or possibly 87) on the relay should get +12V at all times. If the voltage is present at the relay socket and you still have the old relay, try removing the plastic outer cover of the old relay, then install it in the socket. If manually operating the relay causes the fan to operate, the problem is not with the primary power nor the fan, but likely with the pilot circuit from the PCM. If manually operating the relay does not operate the fan, start looking at the fan motor itself and the wiring to it.
I had a Blazer with a similar problem and I finally discovered a failing bus wire in the underhood fuse/relay center. A used unit from the salvage yard fixed that.
Make sure there is a good 12V source at the relay socket. Pin 30 (or possibly 87) on the relay should get +12V at all times. If the voltage is present at the relay socket and you still have the old relay, try removing the plastic outer cover of the old relay, then install it in the socket. If manually operating the relay causes the fan to operate, the problem is not with the primary power nor the fan, but likely with the pilot circuit from the PCM. If manually operating the relay does not operate the fan, start looking at the fan motor itself and the wiring to it.
I had a Blazer with a similar problem and I finally discovered a failing bus wire in the underhood fuse/relay center. A used unit from the salvage yard fixed that.
Helmuth48
11-13-2010, 09:30 PM
Blue Bowtie is right on the money...I have a spare old relay ( cover removed) for troubleshooting the cooling fans all the time.... Also check for a "good clean" ground to the fan....
Cheers Mate....
Cheers Mate....
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