Dual Cooling fan turns on after truck is off

[Srvelis1]

I have a 2005 1500 silverado and the radiator fans are staying on after the truck is off and drained my battery dead. Replaced the relay but no luck there. In addition SES indicated knock sensor code. Had the knock sensors, cleared codes, and SES has not turn back on, but the cooling fan is still draining the battery. I read some post about Powertrain Control Module being relate to both.

 

*knock sensors replaced*

 

Any suggestions?

[chas0218]

I would check to make sure the on/off wire is connected into your ignition and not wired constant on.

[bgee134]

We have had this problem with the police package impala. GM actually issued a service bulletin to install an updated relay harness kit which eliminates the relays from the fuse block.

Your problems, other than stuck on relays could simply be the control wires shorting to ground...inturn keeping relays energized, keepibg fans on.

The GM Tech II scan tool is exellent in helping diagnose this.

Knock sensors have nothibg to do with cooling fans by the way.