I have dual electric fans and was wondering why is there two fan relays? Is one for each fan? If so, do you think it is still possible that my fans are not coming on because the relays may need replaced? I mean, two relays are not going to all of a sudden go bad at the same time, right? If it was a relay problem, one of them should still click on seeing that there is a relay for each fan right? For example, if the relay which operates the a/c controlled fan is good, it should click on when the a/c is turned on. Basically, I need to know what the purpose of two relays for the dual electric fans? Also, should I replace both relays, because the fans do not come on at all. (I checked fuses and turned on the a/c)

 

yes the relays for the the two fans. One fan the primary one (left) is controlled by the coolant temp sensor which sends a signal to the ecm and the ecm says "turn on. The other is controlled by the fan switch or if u turn the a/c on. The fan switch will tell that fan to come on at a higher temp then the primary one. The primary turns on at around 220 and the secondary turns on at around 240 or something.

 

The ECM has nothing to do with fan operation on these cars. It's the fan switch and the A/C.

 

Ah yes the ecm has something to do with fan operation. If you ever have a scaner hooked up to your car you will the ecm has a spot for the fan being off or on. Also thats why you have two coolant temp sensors. One for the gauge and one for the computer. Also loudmouth is right. the fan comes on at 220 and the second fan will come on at 240 or if the ac is on.

 

ECM controls the primary fan (Fan1) Fan2 is listed but I don't believe changing the on/off temp on that one will do anything,

 

I think fan two is controled by the ac. Check the ac wiring scimatic and I am pritty sure you will find it.

 

It's controlled by the A/C pressure switch and the the temp switch in the pass side head. those are wired in parallel.