#2 Cooling Fan Runs on High after Ignition is off for a very long time
 

Just started up my 2001 Alero GLX with 3.4L and let it run for a while. It had been sitting for 6 months and when I shut it off the fan was running. Went into the house and 45+ minutes later the fan was still running on high. I started up the car and the fan shut off? Turned the car off immediately and the #2 fan turned on running at high speed again. After another 30 minutes I switched the relay with the #1 fan and the issue persisted. I pulled the fuse. Note outside temp today was 55 degrees and car only idled. This has to be something simple. Any Help?

Sounds kinda wierd.. bumpity bump for the confused individual lol

maybe it can help, i seen one time, the fusebox panel in left of dash defective there was corossion and some curcuit were shorted and some other completely destroyed ???? it was not visible by eye, I had to completely take the fusepanel apart to see that...

There was only one fan on? That's not normal. The fans ALWAYS come on both at the same time. That's how they're designed. Also, there are 3 relays for the fans.

i have an issue with my fans too.. my fans don't kick on unless i kick the A/C on.... but the Coolant Temp sensor was replaced when i had to do the head job on my engine... any ideas

Does your gauge work right?

Thanks for the input. I will check to see if the ground strap to the fuse panel is corroded, thought about that last night. Had the under hood fuse panel out last winter and it was good. The vehicle has seen little mileage since then, but I will not rule that out.

Cliff, I know the fans have 3 mini fuses one is for ground but I will double check the relays. You might be correct on the fans both running. Maybe the #1 fan is shot and the PCM triggers the #2 fan to run? I will need to make some phone calls to some buddies. I have lost my ability to look this stuff up at work. It might be time to purchase an OEM service manual as I have 3 Aleros in the family now.

I have run past this before but cannot remember.

01OldsAleroGT – The PCM (Pewrtrain Control Module) controls your fan operation. The fans are programmed to run when you’re A/C is operating (generally speaking but do not quote me as I did not write the software for this powertrain system platform) or your engine coolant temperature is over a certain threshold. If you sit in traffic, and can hear over the other noises, your fans will turn on without your A/C being on if you engine gets that hot. Especially in Florida in the summer. There are threads on this topic here

Sorry for posting this under the New Members Intro – I was in a frustrated place then and not thinking correctly.

Welcome aboard! I'm going to move this, though, to the proper section.

The fans are only controlled together. It's possible with some combination of a bad relay, fuse or wiring condition that one will run though. They either run in series (low speed) or parallel (high speed)

That's an odd one.

Do you have any aftermarket fan switches or PCM ungrades