Been lurking the boards for a little while now, but finally signed up. I have a 92 Firebird base model 3.1L V6. Problem I am having is it seems to be running a little hot. I let it run idle for a while, but was impatient and it never reached the 226 or whatever it is that kicks on the fan, but even with the AC on the fan would never turn on. Also, during this time the upper radiator hose was very hot, but wasn't "full". It felt as if some water was going through, but not much if any. To be proactive (or maybe just insane) I replace the water pump, thermostat, and the temp. sending sensor.

Flash forward to this afternoon when i finished. First time I cranked it up the fan kicked on right away (AC was on) but died quickly. Realized I had forgot to re-connect some wires, hooked them up and restarted it. Everything seems to be running the exact same, including the fan will not kick back on even when AC is on. The only difference is, after starting it back up the temp gauge went nuts...bouncing all over then dropped down to 100 and sat there even as it heated up. Am I missing something here, or is perhaps some other electrical problem frying the temp sensor? Pretty much at a loss now. I read somewhere on here the gauge is fed through something besides the temp. sensor....where is it fed from? Anything offhand that might fry the sensor? Anything to keep the fan from kicking on?

Thanks

 

Ok, let it idle a while, and even though the hose felt hot, it was showing 100 degrees is all. I unplugged the sensor, and the fan kicked on, but gauge stayed the same. Am I confused on what sends the signal to the gauge? I was thinking it was not the sensor, but something else. A few minutes ago though I read something some where else to the contrary. Thanks for any help

 

Not sure on a V6 car - but the V8 cars ...

TPI dual fan cars have a coolant temp sensor in the front of the intake - these tell the ECM what temp is, and thuis ECM turns on fan. It has 2 wires, one yellow one black. Then there's a fan switch in pass side head, that turns secondary fan on as well - this one has a single wire with a weird mushroom connector like the knock sensor (which is in pass side block).

The single fan cars just have the fan switch in the pass side head with the mushroom connector.

ALL V8 cars the gauge is fed from a temp sender on driver side head that has a single wire that is green.

Not sure if that helps you on a V6 car.

 

Thanks, that's what I was thinking, that the sensor only sent info to the computer. Will have to look for the mushroom connector and see if maybe I knocked it lose or something when I was swapping the water pump.


Still can't figure out though why the fan will not come on at all (only did that one time on first crank after working on it), unless I unplug the temp sending sensor. Also, I check the relay for the fan by turning on the AC when the key is on and again while idling. Nothing, but like I said unplug the sensor and it kicks right on. Maybe the sensor was bad from the store, I dunno...later I'll test the old one in hot water and check the resistance. I just hate having things unplugged, but rather have the fan running than not.