Silly question but its driving me crazy. My fan doesnt come when my 91 camaro LO3 is hot but it comes on when the A/C is on. Leads me to believe its the fan switch. I replaced the coolant temperature sensor which was at the front of the intake manifold. I then replaced a sensor that was on the driver's side cylinder head near plug#1 but all that did was make my guage not work. So it must have been the sensor for the coolant guage. How many damn sensors does this thing have that read coolant temperature? Anyway, does anyone know where the real fan switch is?

 

I don't know if the 91 is like the 86 but my fan switch is on the passenger side of the block up between the #6 and #8 plugs, very hard to see and even harder to get to. hope this helped.

 

thanks for the info. I'll try it out tomorrow.

 

Thanks redbird, you got it right. The fan works perfect now.