I have 91 Camaro stock with a 305 engine. The car has one fan. I have changed both temperature sensors, but the fan will not come on unless I turn on the AC. What will be my next step to try and troubleshoot the problem?

Thanks,

94 Z-28

 

you replace the fan switch in the passenger side head?, or just the ECT in the intake and the gauge sensor in the drivers side head?

 

check that fan relay,, make sure the passanger side fan motor is good

 

X 2.

 

If the fan does come on with the AC, then the relay is fine. Its probably the temp switch in the passenger side head, as mentioned above.

 

Does any one know if that is a switch or just a thermo-resistor?

 

http://www.hypertech.com/Products/Cool%20Fan%20Switch

I prefer the 200/185 option rather than the 176/166 option.

 

switch

 

Yes, its a switch. When the coolant temp reaches a certain tempurature, the temp sensor grounds itself and that completes the circuit to turn on the fan relay. Below the turn-on temp, its an open circuit.

 

Yep, its a switch.
I picked one up for a 1992 Z28 with a 5.7L for about $5. It is open at room temp even open when I boil it in a pot of water. Must turn on at, at like 220'F then.
I bought one form summit, it said it was a " 200/180 thermostat switch" and they sent me a temp gauge sender. The damn thing was like $20.
I have the electric fans on my truck, just need a thermostat switch to control them.

 

I had/have the same problem. Temp guage pinged out, replaced everything like you, and I ended up installing a 16" fan that comes on at 160 degrees thanks to a $25 kit at the parts store, and I have a 14" fan that is on all the time when the car is turned on. When you find that pesky ground please tell me where it is located.