rad fans kick in all the time

[Peter E]

Hello everyone

I posted a question on this recently, but couldn't quite figure out the answer. I have a 2001 Alero with 3.4L engine. Recently, my coolant temp gauge stopped working and both my rad fans kick in right away. I don't believe the thermostat is stuck open, since there is decent heat coming from the heater core.

Is there a fairly easy way to diagnose the problem without a scan tool? Coolant temp sensor? Fan relays?

thanks for any assistance

Peter

[Iflylow]

Coolant temp sensor is bad. The computer cannot determine the correct coolant temp, so to be safe, it turns the fans on all the time. That's why you have no coolant temp on the guage either-no signal from the sensor to the computer.
Bad fan relays would not affect your guage.

[Peter E]

I changed the coolant temp sensor but it didn't make any difference. Do the error codes need to be cleared after changing a sensor? If so, is there a way to do it without a scan tool (disconnect battery??)

thanks for any advice

Peter

[Iflylow]

If the new sensor solved the problem, your temp gauge would work again, and the fans would work right, also. The code would not need to be cleared. In fact, it would clear itself after several drive cycles.
Maybe you have a wiring issue. Check to see if you are getting power to the temp sensor, and then check continuity between the sensor and the other end of the wire.
I would suggest getting Autozone to scan it for you. They do it free around here. Post the code you get and we'll go from there.