Please help!
I have a 92 rs with a 3.1 6 cyl. and an auto tranny.
The car overheats at long stop lights or any drive through.
The electric fan only will turn on when the ac is on or i unplug the coolant temp sensor. I have no trouble codes(unless i unplug the coolant sensor).
I have replaced the coolant temp sensor, relays and the ecm(twice).
I would love some help on this problem, I am just not sure what to do next. I want the car to be right without hardwiring the fan to a toggle.
Thanks!

 

Are you changing the right coolant sensor? There is the one for the computer and the one for the fan. The circuit is pretty simple. Once the sensor sees enough heat it turns on the relay that turns on the fan. Get a diagram and a test light and see where the power is and where it is not.

Also a 92 is a 3rd gen you posted this in the 4th Gen area.

 

I didnt know there was more than one.
I changed the one on the center top of the motor, by the thermostat.
Where is the other one or ones?

 

u are in the 4th gen section. info i have is from a 93 so im not real sure its the same as yours. if u havent, check the #6 fuse in the fuse box under the hood. its a 10 amp fuse and should go to the fan control relay.

 

Make sure your radiator is topped off and there is no airpockets in it. Don't believe the sensor will turn on a fan unless it actually has water temp to tell it to.

 

my 92 has the same problem but the guy i bought it from unplugged the air con. an now when you turn it to a/c max it acts as a fan switch .
i'm use to watching gauges so it's no big deal for me plus mine only does it in town . i never use the a/c anyway so it's a great fan switch for me.

 

My '96 does the same thing... I've replaced everything in the system except the PCM, and was going to do that next... I might wait, if you've replaced the computer and that didn't fix it, LOL. Let us know if/when you figure this out.

 

Hey nnewquist,
I see that this is a common problem!
I have read everything in every forum and see no answer to our problem.
I will keep asking and someone hopefully can help.
Don't change any computers, that was a huge waste of money.
First I put in an aftermarket one and was told that was still my problem.
I then went and spent more $ on a OEM delco one and BAM, nothing!

 

The one for the computer looks like it is located down next to the exhaust manifold on passenger side of the engine either next to the auto tranny dipstick or oil dipstick. (picture is not all that clear) The other one, is the one that you changed located top front LH side of engine. From reading online, the sensor located in the engine block sends voltage to the ECM that helps determine control of fuel delivery system, torque converter clutch, eng timing, canister purge, idle air control and COOLING FAN. It also says that low engine coolant will also affect the ccoling fan being energized at the right temp.

 

Osduck,
I went looking around this mornig and only found one sensor on the passenger side.
It is located just in the front of the starter and not by any dipstick. It does not look like it's a coolant sensor. It is quite a bit bigger and looks like its the knock sensor.
Where could I find the picture your were refering too?