regalrobert

The cooling fan on my 99 cav will not run. I replaced the relay, and it did not help. I just had the temp sensor changed and am going to try it again. Right now I have the fan hard wired through a toggle switch to keep the engine cool when it is running. What else should I look for if it does not work when I take the toggle switch off?

J-Ri

Did you check the fuse?

Don't just go replacing parts, test things before you replace them. I believe there is only one temp sensor on the 99s and the PCM uses that input to give an output to the gauge, so if the gauge reads hot, the PCM knows it's hot and should be commanding the fan on. Gauges can be off, I have seen them as far off as 50 degrees from what the ECT sensor reads (which puts them in the red at normal temp). Verify with a thermometer that it is actually running that hot before you go any further.

Also check that you replaced the correct relay, I know it sounds simple, but I have seen it done before. Check for power with a voltmeter (don't use a test light as some will damage the PCM by drawing too many amps) to two of the terminals for the relay, the other two should have ground. If not, you'll need a wiring diagram to see where the wires go.

__________________
'04 Cavalier coupe M/T 2.2 Ecotec
Supercharged 14 PSI boost, charge air cooler, 42# injectors
Tuned with HP Tuners
Poly engine/trans/control arm bushings

When you buy something... a bottle of pop for example, who gets the profit from it and what do they do with it? Maybe your money's going to groups that want to hurt you. I think everyone should do a search for things they purchase regularly "____ supports". Might just find a company you won't buy stuff from anymore.