usual cooling fan issues

super-merc

Registered User
I know its been awhile since I have asked a question but most of my problems have been solved just by searching and reading everyone's threads.

My '95 manual was cooling great then the auto climate control smoked and blew the run fuse under the dash and the 5 amp mem fuse under the hood. Heat went to full hot and wide open heater fan. Replaced the unit and fuses and heater/ac is behaving like normal but now the temp creeps up until the check gauges light illuminates. Neither fan comes on at any speed. I can turn on the AC and the engine bay fan comes on and seems to be running on high. I can shut off the AC and the fan will continue to run for about a minute before shutting down.
I suspect the IRCM as the temp switch (not the indicator) has been replaced prior to my buying the car, but only have a spare for my '90 XR7.
Are the two units the same?
I have not tried to unplug the temp switch and verify the fan operation. The car cools with the AC on but here in northern Florida the outside temp is pretty nice at the moment. I checked the coolant level and haven't opened anything up recently either.
Sorry this is so long but I am a MC-130E crew chief and we are taught to give all the input conditions for troubleshooting.
Thanks, Rob
 
Pull the connector on the ICM temp sensor (not a switch), and see if the fan turns on.

If it comes on with the A/C, it's probably not the IRCM, but the ECM not flagging the fan needs to come on - which would be the ECM's temp sensor (the two-wire one.)

RwP
 
Thanks for the help, I will try that this weekend. Is there any difference between a 1990 and 1995 model ICRM? Is there a difference in the auto climate controls on 1993 to 97 models?

Thanks again,
Rob
 
Again, thanks for the help. I assumed the switch was ok because it looked like it had been replaced recently. I pulled the connector off and the fan worked fine, changed the switch and all is well again. You guys are the best:)
 
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