Cooling fan on all the time 1999 corrolla

If the fans are on, the relays are probably fine.

Check to make sure that the connectors for the fans are all properly plugged in.

What is the coolant temperature reading on the instrument panel?

What is the condition of the coolant and cooling system, especially the radiator and thermostat?

When is the last time the coolant was changed?

I believe these are set up so thatif there is a failure, the fans turn on rather than stay off. That way, if something fails the fans are on, rather than not turning on and resulting in overheating. I noticed this on a Nissan and a Mazda I had.

I think what's happened is the temp sensor mounted to the radiator has gone bad. That's where I'd look first.

The coolant was changed last fall and the temp is normal range, The sensor is it actually located on the radiator, or thermostat housing ??

obliged Dave

"$)Chachiroku_+O+A+m+/" wrote: > On Sun, 11 May 2008 11:27:23 -0500, Davey wrote: > > > Hi > > > > The Cooling fans are on from the time the ignition is turned > on , What > > relays should be checked, your help is really appreciated, > > > > Thanks > > I believe these are set up so thatif there is a failure, the > fans turn on > rather than stay off. That way, if something fails the fans > are on, > rather than not turning on and resulting in overheating. I > noticed this > on a Nissan and a Mazda I had. > > I think what's happened is the temp sensor mounted to the > radiator has > gone bad. That's where I'd look first.

IIRC, the sensor for the fan is located in the radiator. Follow the wiring from the fan back, and you should see where it plugs into the sensor. It may make a stop at a relay first.

They didn't have a '99 at AutoZone, they did have a '96. Try this:

Get to know AutoZone. They have a lot of useful information and pictures that can identify parts and give clues as to where they go and how to get them out! ;)