I have A/C with large core rad (I think) plus factory oil cooler. I also have two factory fans and I have never seen from the driver's seat the right hand fan working, only the left.

Does anyone know under what circumstance the right should be working ?

thx,
RP.

 

When the AC turns on that's when that fan will turn on.

 

That is what I am concerned about. I think it may be that fan does not turn on. I have turned the a/c on when the engine was at operating temp and the 2nd fan did not start. A few times I have gone to high temps with the a/c on while stuck in traffic and I was thinking that fan probably is not working ?

Any idea how to test it ?

thx,
RP.

 

On dual fan setups the primary fan relay(driver side) is located below the radiator cap mounted to thew metalwork, the secondary relay is usually mounted to the inner fender above the battery. You can pull off the relay connector and jump the two heavy wires and the secondary fan should come on. Or you can just swap the relays and turn on the air and see if the secondary fan functions. The relays are a real common problem.

 

i have the same problem. i tested everything. everything is good. i heard from several people that the passenger side fan is just a "back up fan". it doesnt come on until like 230.

 

The secondary (passenger side) fan is controlled by the fan switch located in the passenger side cylinder head. Check the relay like was said and check the connection at the switch, too.

 

Primary fan turn on occurs at approx. 225 deg., secondary fan at 238 or as AC pressure dictates.

 

FWIW, the primary fan also comes on when the AC is turned on.

 

As I recall the secondary fan rarely kicks on until some extreme temperatures 230+ are experienced AND a/c is on... just give it a 12 volt feed and see if it kicks on, if not, the motor should be a cheap easy replacement. I go through mine every 3-4 years on a single fan setup. If the second one rarely comes on, maybe particulate got stuck in it and just busted from non use...

 

see my post for an easy fix.https://www.thirdgen.org/techbb2/sho...hreadid=118985

And danno, the relays in my car are located in the firewall by the driver's side fender.

 

yeah the passengers side fans comes on when:

1. engine temp is like around 238 using the fan switch on the block between the 6 and 8 cyclinders
2. when the a/c pressure switch is activated (i.e when the a/c is on, fully charged and builds enough pressure

i would start by messing around with the passengers relay, just find it usually around on the drivers firewall, i had three in a row it was the all th way on the right i believe.

just get the relay off and measure the voltages with a voltage meter in the connector where the wires are, after that jumper the always hot (even when the key is not in the car) with the ground ground, they are the two heavier size wire, and the fan should come on, if it doesnt it seems like the motor is gone.

but if the fan does work, then its most likely a/s pressure switch; its either broke, not hooked up, or the a/c does not have enough charge to build pressure.