98 Avalon - 2 radiator fans, when should they both be on?

[drh]

It seems like the passenger side radiator fan is always on -- I thought the second one on the drivers side was supposed to come on when you turn on the A/C. But mine doesn't come on when I turn the A/C on. Is it connected to some temp. sensor? Anything else I should check?

Wife said that yesterday while stuck in a traffic jam w// 107 temp outside the gauge got one notch below red. Switching to fresh air/killing the A/C cooled it back down. Was fine when her speed picked up. I've seen the gauge go up a little above normal in a stop and go situation (and really hot outside) but nothing like that before. So I drained and refilled the radiator and that's when I noticed the other fan doesn't seem to come on.

[BonzoGonzo]

the fan may be dead. disconnect it. use a trouble light to find voltage. it certainly should be there, any time the a/c is on and the speed is zero...

could be the relay. fan1.

could be the temp sensor but if it does not work with the a/c on, i doubt that is the problem... more likely a dead fan. they aint cheap!

[drh]

Originally Posted by BonzoGonzo

the fan may be dead. disconnect it. use a trouble light to find voltage. it certainly should be there, any time the a/c is on and the speed is zero...

could be the relay. fan1.

could be the temp sensor but if it does not work with the a/c on, i doubt that is the problem... more likely a dead fan. they aint cheap!

Thanks for responding BonzoGonzo.

Fan 1 relay checks out ok. I pulled the connector for that fan and hooked up my voltmeter, its getting 12V. But whats weird is that its getting 12V even with the A/C off. Maybe because its so hot (outside temp) it goes ahead and tries to kick it on anyway? Either way it looks like the fan motor is dead.

You've got me scared to see how much these fans cost now.

[robcam13]

can you switch the connectors between the fans (plug fan 1 into fan 2 and vice versa) and see if the problem follows

[BonzoGonzo]

Originally Posted by drh

Thanks for responding BonzoGonzo.

Fan 1 relay checks out ok. I pulled the connector for that fan and hooked up my voltmeter, its getting 12V. But whats weird is that its getting 12V even with the A/C off. Maybe because its so hot (outside temp) it goes ahead and tries to kick it on anyway? Either way it looks like the fan motor is dead.

You've got me scared to see how much these fans cost now.

yeah. your voltmeter is a very high impedance device. use a test light. it will draw a little current and make those "ghosts" disappear...

the amount you'll find for those fans is outrageous. try 1-800-radiator... they are the suppliers to autozone, etc, and they will sell direct for the same prices. they sell chinese cr*p, but it works... when i heard almost $200 for a !@#$%^&*()!! FAN, i 'bout coraked! and it would have been the same thing, just marked up about 125%...

you might swap connectors, as he said, but i think they're on opposite sides of the radiator and getting the wires loose so you could make it to the plug on the other side would be nasty... but you might remove the fan that's dead, and do it that way?

[Blu08Taco]

Try a junk yard. Paid 15 bucks for a radiator fan with the housing.

[fourwheeler]

Or try hooking 12v directly from your battery to the fan motor to confirm the fan motor is dead.