Driver's side fan runs all the time after engine starts. This fan motor actually burned up as a result and melted the fuse link over by the battery. None of the wiring on the car is hacked up or modified (no under dash switches, etc). In my past experiences, usually when a cooling fan switch fails they fail opened.

Also, the aux fan doesn't come on when the a/c is engaged. I jumped it and it runs fine. Relay works also.

What's going on here?

(I searched and was overwhelmed with results. Nothing seem to fit this scenario)

 

Aux fan is controlled by the switch in the passenger side head, just forward of the dip stick.

Since it's not coming on with the AC, but does when jumped means the wiring is good and you have a bad relay on that circuit. The dual fans have two relays.

That should fix your aux fan.

Have you fixed the wiring and primary fan yet?

For the primary, it's controlled by the ECM. If it's running all the time, that's because the ECM thinks it needs to. You need to trace that wiring and find out why. Could be the sensor on the front of the engine block that's telling it that it's hot and needs to turn on. Could be a bad ECM. Could be something is grounding out between the sensor and the ECM making it "act" like a 'hot' signal to the ECM.

 

Thanks for the note. I did check the wiring and it is good, nothing is grounded or hacked up. I also repaired the burned up section by the fuse link for the main fan. Both relays check good also. I swapped them around and tested them multiple times, they're working fine.

I purchased a 195* fan switch that I am going to install on the passenger side head in place of the factory aux fan switch. I am also going to install a 180* thermostat in the engine. I'll wire the new switch to both fan relays and control them both with it. They'll come on at 195 and go off at 175. Only thing I'll have to make sure of is that the hot wire going to the coil in the relays is only hot when the key is on - don't want the fans running the battery dead while the car is parked with the engine off.