The radiator cooling fan runs and keeps engine cool when the air conditioning A/C switch is turned on, but will not run and engine overheats when air conditioning A/C switch is turned off. I understand that the fan is supposed to run constantly when A/C compressor is engaged to move air through the condenser core. Any suggestions as to why the cooling fan will not run while A/C switched off.
Define 'overheats'.
How high does the needle go on the temp gauge?
Lane [ l a n e @ p a i r . c o m ]
Your fan is not getting the signal to turn on. The signal comes from your coolant temperature sensor. Your car is 7 years old and this might need replacing.
Unless you flush your radiator anually, it's not uncommon for this thing to fail. I'm pretty careful with my car and mine has failed finally at 10 years / 156,000 miles. Saturn wants about $140 to change it.
The coolant temp sensor costs between $15 and $20. The thermostat costs about $30-35.
There's a difference between the thermostat, which regulates flow of coolant to the engine, and the coolant temp sensor.
The temp sensor is what sends the signal to your fan to turn on and off.
Chilton's manual shows how to replace the thermostat. Not sure about the sensor.
Barry
I recently have a problem on my SL2 1993. The fan start only when the temp reach the red zone on my gage. I changed my TCS ( Temperature coolant sensor ) and now he work fine.
This sensor send the temperature to the PCM ( computer ) and an output on the PCM unit start the fan.
Claude
"Lane" a écrit dans le message de news: snipped-for-privacy@corp.supernews.com...
...with Dexcool you don't flush yearly (typically).
No, GM says you don't have to because the EPA wants them to say that. I sure as hell wouldn't trust that dexcool stuff, given the troubles they've had with it....
...yeah, I remember a while back on a coolant thread one guy mentioned getting the Dexcool out of his vehicles and using vanilla ethylene glycol and flushing regularly.
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