2005 Chevy surburban fans don’t work

[Doubeleive]

It never overheats. It runs a little high at idle in town but that’s it.

you might want to pull the pcm harness off and take a look and see if there has been any water intrusion or if there is any corrosion on the pins. if so that would need to be cleaned up and could be a reason for the fans not working.

 

[Marky Dissod]

Two criteria normally turn on the electric fans: coolant temp and AC pressures.

Also my AC system is not operating and it is not filled with refrigerant.
It has a leak and I’m waiting on parts to replace compressor and drier.

Your non-working AC will never turn the fans because it will never reach the fan-on pressure threshold without any refrigerant.

That leaves engine coolant temps as the only criteria that can turn the fans.
I don't have the GM OE coolant temp thresholds ...

It never overheats. It runs a little high at idle in town but that’s it.

but one of the MANY reasons why I keep saying y'all should get your vehicles tuned, is because GM likes to set the fan-on thresholds pretty high. Not high enough to OVERheat, but high enough to improve your POTENTIAL MpG by 1 or 2.

... I found that my fans are not coming on. So I unplugged the temp sensor and they run high speed. So I replaced the temp sensor and they still don’t come on.
What do I do?

If you want your engine to run cooler,
GET TUNED.
If you want the AC to turn on the fans, get your AC working properly again.

 

[Chevywalt66]

I noticed that my truck has electric fans and has a fan and fan clutch isit suppose to have both fans. Please help

 

[Marky Dissod]

You mean your truck has 3 fans?
Pics, PLEASE.

 

[Chevywalt66]

You mean your truck has 3 fans?
Pics, PLEASE.

Ok. Sending now

 

[Chevywalt66]

And yes typical fan with fan clutch and dual electric fans

 

[Chevywalt66]

 

[Chevywalt66]

 

[Marky Dissod]

The mech fan should 'turn on' before the electrical fans.
The electrical fans have three settings: Off, Low speed, and High speed.
The mech fan has a variable clutch so it can more progressively and smoothly adapt to need.

When you asked about your electrical fans not turning on, was the mech fan spinning at all?
Anyone else know more about how mech fans are supposed to work?

 

[Chevywalt66]

Yes the mechanical fan works all time. Never seen it cut off. But what I r read was Chevy did away with mechanical fan in 04 and went to electrical. I don’t thinks it’s suppose to have both fans