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My 2000 SSEi radiator fans run constantly no matter what the temp is outside.
The defrost is off, in fact I shut the climate control off (pushed temp control buttons off) and the fans will not shut off. Could there be a defective sensor or relay. When I start the engine the fans come on at low speed then after about 5 seconds turn on to high speed, no wonder the temp gage is indicating well
under the 180 degree stat temp.
Thanks for your help Guys

Smells like a bad relay. I'd find out the location of the fan relay and swap them around to see if that changes the problem.

Any check engine/gauges lights on the dash, or DIC? Do they run after the key is turned off?

No Check Engine lights or DIC info, the dash looks normal.
Fans shut-off when ignition is turned off.
Thx

There are 3 relays in the underhood fuse block that control the fans. Fan 1 for low speed; fan 2 for high speed; and cooling fan s/p (series/parallel).

As LeSabre mentioned, try swapping them around and see if symptoms changes. It may help narrow down where the problem lies. Any relay with the same number can be used.

I will do some relay swapping tonight!
Thanks

sparky wrote:My 2000 SSEi radiator fans run constantly no matter what the temp is outside.
The defrost is off, in fact I shut the climate control off (pushed temp control buttons off) and the fans will not shut off. Could there be a defective sensor or relay. When I start the engine the fans come on at low speed then after about 5 seconds turn on to high speed, no wonder the temp gage is indicating well
under the 180 degree stat temp.
Thanks for your help Guys

It could be a bad sensor for the temperature. I do not know if the indicator gauge uses the same sensor as the computer uses. It would require checking the computer's value to determine if the sensor is wrong. Is there any chance a connector or wire has been broken on a sensor due to working around the engine?

sparky wrote: no wonder the temp gage is indicating well
under the 180 degree stat temp.

Actually the thermostat should raise the temperature of the coolant to the 180 degrees without regard to the fans cooling the radiator fins; the coolant shouldn't be circulating through the radiator at all beyond a minor bleed rate through the thermostat . You might want to check your thermostat. The heater gets circulation and if it's been very cold and you have the heater fan pulling lots of heat out of the heater core, the coolant might not be able to get up to 180 degrees. My own suggestion would be put in a 195 thermostat for winter. I switch thermostats for winter and summer; one is a GM that runs cooler than 195 for summer and other is a Stant that runs up a little hotter than 195.

imidazol97 wrote:It could be a bad sensor for the temperature. I do not know if the indicator gauge uses the same sensor as the computer uses. It would require checking the computer's value to determine if the sensor is wrong. Is there any chance a connector or wire has been broken on a sensor due to working around the engine?

There is only one temp sensor that the PCM uses for gauge indication and fan control. Do you have access to a scan tool?

According to the FSM, and as Archon stated, there are 3 relays that control the fan. They are in positions 37 (coolfan1), 39 (coolfan s/p) and 40 (coolfan2) in the under hood fuse box.

I switched the low and high fan relays around and the cooling fans stayed on.
I pulled each fan relay one at a time, one fan shut off then the other shut-off.
After detremining the fan relays were fine I pulled the connector off the coolantant temp
sensor. I started the engine (started very hard) the temp gauge stayed at zero then checked the
fans and they were still running. Lastly even though I had no check engine light on I plugged in my scanner
and low and behold there was one code P128 (Coolant Temperature Below Thermostat Regulating Temperature). I cleared the code and the fans shut off! Drove the car into work this morning and the coolant definatly heats up faster when the radiator fans aren't running (funny how a P128 code can turn the radiator fans on?) I will be replacing the 180 degree t'stat for a 195 during the winter months.

Thanks all for your help!