2000 Malibu 3.1 V6 - Radiator fan won't turn on

[IanSzgatti]

Yes, they should both be on under the conditions you talking about. You need to have live data to see what's happening, or you need to identify the correct pins on the ECM and verify you have signal.

[SkortchGT]

ultimately you need the ECM to command both fans on. both fans do work, circuit must be good, suspect ECM problem.

i do ask though, have you ever seen both fans actually work? has the car been over-heating lately?

I was thinking about an ECU/ECM problem before I went to bed last night, since like you said the ciruit seems to be good. The car has never overheated on me. Shouldn't both fans turn on if the A/C is turned on?

[IanSzgatti]

ultimately you need the ECM to command both fans on. both fans do work, circuit must be good, suspect ECM problem.

i do ask though, have you ever seen both fans actually work? has the car been over-heating lately?

[SkortchGT]

Hi all,

I recently bought a 2000 Malibu V6 and just did the LIM gasket job (see this thread: http://60degreev6.com/forum/showthre...&highlight=lim).

I'm now having a problem with the driver side radiator fan not turning on. I understand these engines tend to run hot, and both fans usually kick in at a higher temp. For some reason, I can never get both fans to run together, even with the A/C on.

Today, I replaced all three fan relays, coolant temp sensor, and even replaced the thermostat again. The passenger side fan is the only fan I see turning on. Funny thing is, if I manually trip the relays, both fans will turn on (so both fan motors are good), although they never kick in together when the car is running.

As a test, I parked the car and held the RPMs at 3k until the coolant gauge hit close to the red, and the light dinged and came on indicating the car is in the "danger zone". This process took about a half an hour. The entire time the only fan that was running was the passenger side fan, even with the a/c on. The car didn't spew any coolant (i finally have the system bled properly), however I just can't get both fans to run together. The only one I see running is the passenger side fan.

Any help or input anyone can provide is much appreciated. Thank you in advance!