My passenger side cooling fan is not working. I put a new ECT sensor on it last week. I put two new ac delco fan motors on it two months ago. But the funny thing is when I unplug my MAF sensor they both work. So it ain't the fan motors. What could the problem be?

 

So, like when you turn on your a/c, you only get the driver's side fan to come on? (that's low speed) ...but both work at high speed when you disc the MAF?

I would swap your fan relays one a time with the fog lamp relay. I suggest #3 first.

 

I haven't tried it with the A/C on. I'll go try and see if it does and try switching relays around and see what happens.

 

Sorry it took so long to answer back but I'm never on the computer through the weekend. Tried it with a/c on and switched relays around and one fan is all that'll come on unless i unplug MAF. I'm lost anybody else have anymore ideas.

 

See if you can unplug the connectors at the fans and swap them. Now see if the passenger fan works and the driver side does not. That will absolutely prove it is not a fan problem.

Can you read and troubleshoot from a schematic ? The lower diagram is what you have.

Has anyone ever messed with the fan wiring? Your trouble seems very odd if you are accurately describing what it is doing.

 

I'll try that tomorrow evening and see what that does. I'll also take a closer look at that schematic. Yeah I'm accurate about the problem, the only time the passenger side fan will kick on is when the MAF is unplugged.
Shoebox, I just thought of something, a few months ago I had a problem with my engine idling fast so I took it to a shop and had it scanned. The computer threw no codes but the diagnostic showed the throttle open at 8 degrees. They told me it was either the TPS or my computer was bad. I went ahead and changed the TPS and it fixed it. Is it a possiblity that my computer is shot because I have had a lot of electrical problems since last summer.

 

I would not blame the computer at this point. I still think it could be a relay or wire problem.