I only have one cooling fan coming on in my engine. Any ideas why it might not be coming on? It's the passenger side fan that won't come on. Thanks! Matt

 

It could have a bad motor, relay, wiring, the list can go on for a long time. Check all the fuses first, thats really easy. Check for power at the motor. Try to tap the side of the motor when the car is running at operating temp. If it starts to run once tapped, change the motor. You situation will most likely be more complicated than this, but it gives you a few ideas to start with.

 

the fans come on at differen't temps.. the seconday fan cuts on at 238* i believe..

 

Also the pass. fan is controlled by a switch in the passengerside head

 

Okay, when I put the paperclip thing in to do the diagnostics check, only the drivers side fan came on. They should both ome on right? Thanks! Matt

 

nope. only one fan turns on when u jump the ALDL A and B terminal. the secondary fan is not connected to the ECM

the 2nd fan comes on when the temp reaches 238* or when the A\C is turned on. (if u have A\C)

 

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here's a diagram that might help.