[Spiral]

I have a 89' camaro and it has an electric fan in it. now what i am wondering is why for some reason it won't turn on unless the A/C is turned onto MAX. Then it works. I don't know if I have to leave it on the A/C or not but I do know that much. How can I fix the car so that the fan is running like it's supposed too?

[tom3]

These fans run from AC head pressure at about 235 psi and engine temp at 220 degress which is pretty hot. Have to cover front of radiator and let the engine get pretty hot to see if it is messed up. Runs off a temp sensor that sends signal to computer which sends signal to relay that controls the fan motor. Gets complicated. tom

[Dave Birdwell]

Most Gm cars are set so when you turn the air on, the cooling fans come on. Do you have an overheating problem?
The fans are set to come on somewhere around 235-240 degrees without the air on, and I think this is too hot. When the car was new, the temp would go up, the fans kick on, and the temp would drop to about 200. After the car ages a few years, the radiator gets some gunk in it, and the thing just doesn't cool like it should. Best thing to do is just leave the air on. The other alternative is to get a HyperTech chip that runs the fans at a cooler temp.

[corvet4713]

you may have a bad coolent senser or a bad fan relay if one of these are bad the fan won`t work