Rad Fan Help Needed


Swapped an 88 V6 into an 87GT. Utilized the 87 harness (88 was mated to a 5 spd, 87 to an auto). Started the car and the temp gauge pegged at 100 degrees and the radiator fan never came on. So I proceeded to do the following in an effort to troubleshoot the issues....

Replaced the coolant temp sensor---- Gauge no longer pegs on 100 degrees (problem solved, I believe).
Turned on the A/C----- Fan runs.
Grounded wire to fan switch----- Fan runs (fan, relay and wiring good, I believe).
Replaced fan switch (Rodney's low temp)---- Fan still does not come on (???????).

Current status---- Start the car and run for about five minutes or so. The temp gauge slowly climbs into the red (I shut it down before it does). Fan never comes on. Coolant hoses at the motor and radiator are hot so I believe I have flow. What am I overlooking??? Would air in the system cause the fan not to come on? Is there something electrical I'm missing (temp sensor for the ECM)? Any assistance in troubleshooting this issue would be greatly appreciated.

On a side note.  What happened to the post topic icon on the forum?  Am I blind, because I only see an option to start a new poll?

Did you use Teflon tape on the sensor?

If so remove Teflon and reinstall bare sensor - retry

I did not.  I read the sensor is grounded through the threads so I installed the sensor as is. No leakage noted.

That's great  :D - Do you have Chilton? I think their is a fan checkout/trouble shoot procedure

P.S When I got my Fiero the PO had installed a fan bypass toggle switch - That I didn't know about until I stumbled across it - So my fan had been made manual  }:(

I didn't see anything in the Chilton about troubleshooting the fan.  I have read to test the fan, relay and harness all you need to do is ground the coolant fan switch connector and if the fan comes on those items are operating as intended. I have most of the dash apart at the moment and did not see any type of toggle switch to override the system.  If there was though, I imagine it would have to be switched to the on position or the fan would not come on when the a/c was turned on or the fan switch was grounded.  I like your out of the box thinking.  That's how problems get solved.


[0] Message Index