2005 Chevy surburban fans don’t work

[Chevywalt66]

View attachment 423457

If I disconnect the pcm will I have to re program or anything.

 

[Chevywalt66]

Just had all the relays checked and they work. The temp never goes above 191 at exhaust manifold in ifke

 

[Fless]

It’s a 1500 suburban LT with a 5.3 Chevrolet did away with the fan and clutch in 04 and started putting electric fans in the chevys. So I guess the previous owner noticed the electric fans not working and out a tan and tan clutch in. My guess lol

Sorry, I thought I read it was a 6.0; my bad.

 

[Doubeleive]

If I disconnect the pcm will I have to re program or anything.

NO, disconnect the battery first.... otherwise no telling what could happen by accident

 

[Chevywalt66]

but if the fan cuts on when I disconnect the temp switch could it still be the pcm

 

[Doubeleive]

but if the fan cuts on when I disconnect the temp switch could it still be the pcm

yes, pcm, wiring, temp sensor. they have to talk to each other.
I am not familiar with which pins it is that you could test, @Scottydoggs ?
should be a green wire though

 

[Doubeleive]

this is a different year but might be the same pin on the pcm

I installed E-fans on my 2001

How-To: Installing 06 E-fans on a 2001 This is a step by step tutorial on how to upgrade any 00-02 Tahoe, Yukon, or Suburban to the 05-06 GMT800 electric cooling fans. This same setup can be used on 03-04 trucks as well, however the only difference is the wiring that connects to the PCM. I...

www.tahoeyukonforum.com

 

[Marky Dissod]

When you disconnect the coolant temp sensor (not a switch), the pcm notices that the difference between the intake air temp and the coolant temp no longer make sense.
The fans turn on because it suspects something wrong with the coolant temp sensor - you unplugged it.
If the pcm is programmed with GM OE fan-on thresholds - 226F & 235F - your truck will have to get pretty hot before they turn on, at least until you fix the AC.
If 226F & 235F is too hot for your taste - it should be - get your pcm tuned.

 

[mattbta]

To test fan harness and fans, ground green (C1.42) for both fans low speed, blue (C2.33) for both fans high.

 

[Chevywalt66]

If they both ground and come on at low and high what would that tell me.