Hello. I have 1992 legacy awd with an odd cooling fan issue. Here's the history

 

When I got the car, the Passenger side fan had been hot wired to an ignition 'hot' in the fuse box.

 

I got rid of that.

 

Both cooling fans WILL come on with the a/c button.

 

Fans do NOT come on when Coolant Temperature Sensor is unplugged.

 

Neither come on with both black and green test connectors under dash, connected, as I read, should.

 

Car WILL overheat if I don't turn on the a/c to get the fans running.

 

I had a spare Temp Sensor, but this made no fix.

 

I have checked all fuses and replaced the relays for the fans, both in the engine compartment fuse box and the main fan relay under the dash.

 

I am stumped !!! Probably something simple being overlooked ???

 

my money is either on a partially blown fuze or more likely it sounds like part of your ecu went bad... if you can't get one from a local junk yard I might be able to help with that, there are lots of those cars around me at picknpull.

 

alternatively have you checked all the wiring? voltage drop, impedance?

I actually have a spare ecu that I can try. As for the wiring, no I haven't checked anything more than connections and visual damage, etc.

 

Thank you for your ideas!

Bummer, NOT the ECU. Will check fuses again