Engine Cooling problem
1991 Other Oldsmobile Models 6 cyl Front Wheel Drive Automatic 200000 miles
I have a 91 olds 98 regency. The radiator cooling fans won't turn on at all. I have rerplaced the tempeture sensor and temp swith and still they haven't turned. As you know this causes my engine tempeture to rise when I, m in stop and go traffic or sitting at an idle. I need to know what other things could be wrong and where they're located. Any help would be great. Is there any way I can test the fans themselves? Thanks
Did you check both fuses no.4 40amp and fuse no.16 10amp-if these fuses are okay and you've replace CTS. Its coming from the computer relay control high/low or the fan relay itself.
Checking the fan. Right cooling fan motor connect a jumper wire from the battery positive post to the red and blue wire at the fan connector and black wire to the negative battery post. Fan comes On -its either the computer or the relay.
June, 5, 2008 AT 7:24 PM
I checkeed the fuses first, all good. The fan works, thanks for telling me which wires are pos. And neg. So it must be the relay or a comp. Problem. I would like to know which relay controls the fan? There are 6 relays under the maxfuse/relay center panel under the hood. I checked the one directly under the 40 amp fuse, but it wasn't it. I am having trouble getting some of them off without cracking them. Is there any secret trick, and which one is the exact relay? Thanks a bunch for your help so far.
June, 6, 2008 AT 2:51 PM
See 8 and 9 fan Hi/Low relays below
June, 7, 2008 AT 9:25 PM
I checked the relay and its not it. I jumped the red main wire and the black/red wire at the relay and the fans turned on. I checked the brown wire with my multimeter and it has power with ignition on. Autozone. Com said it was either an open circuit or an ecm ground, but I have no idea where to look for those. Is there any way to ground the ecm again and where is the ecm located and the ground for it? You've been a ton of help so far. I might just wire the fan manualy, but I don't want to damage anything on the computer. I just think its wierd that if it is a bad ground there is no diagnostic light coming on. Thanks again.
June, 8, 2008 AT 11:46 AM
Troubleshoot the fan circuit see below-The computer grounds the relay-when it sees the coolant temperature sensors input signal requiring the fan to come On.