Electric cooling fan clutch

[Wageslave]

While browsing around on eBay, I found an electrically actuated cooling fan clutch off of an Envoy or Trailblazer.

It looks like it would be a direct replacement for a serpentine drive fan clutch, and give you the more accurate temperature control of a fan controller and the ability to switch the fan on with the A/C.

The wiring looks pretty simple as well. Ignore the hall sensor stuff, as it is just feedback for the ECM. All you need is +12v on the Wht/Blk wire and Ground to the Black wire.

Obviously not for everyone, but could be neat if you have a use for it.

 

[fleming442]

Interesting, but I'd rather just throw electric fans in.

 

[pontiacgp]

why make it complicated when you don't need to....

 

[69hurstolds]

why make it complicated when you don't need to....

Because.....GM?

 

[ostrich]

While browsing around on eBay, I found an electrically actuated cooling fan clutch off of an Envoy or Trailblazer.

View attachment 148191
It looks like it would be a direct replacement for a serpentine drive fan clutch, and give you the more accurate temperature control of a fan controller and the ability to switch the fan on with the A/C.

View attachment 148192

The wiring looks pretty simple as well. Ignore the hall sensor stuff, as it is just feedback for the ECM. All you need is +12v on the Wht/Blk wire and Ground to the Black wire.

Obviously not for everyone, but could be neat if you have a use for it.

Not sure if you would be able to control the fan? My buddy has a Trail Blazer SS and we replaced the clutch fan with electric ones from an 4 gen Camaro. The TBSS fan is a PVM fan controlled by the PCM. Here is a short description on what we found when doing things. When we installed the LS1 fans the tune needed to be changed from a PVM controlled fan to a normal electric output.

"As far as the voltage you are looking at, the PCM sends a Pulse Width Modulated (PWM) signal to the fan clutch relay (it's not really a relay, it is an electronic module) and the relay sends this variable signal to the fan clutch. The fan clutch a viscous clutch within it and that determines how much the clutch will engage. This PWM signal can not be measured with a voltmeter, only with an oscilloscope. The fan clutch does not start to engage until the coolant temperature has gone to around 230 - 240 degrees."

 

[olds307 and 403]

Wow so it engages when it is starting to overheat. As said, why would GM have wasted their time with this? If 12 volts turned it on and off sure, might work well, doesn't sound like that is the case.

 

[fleming442]

If the PVM modules work as well as the Corvette ones, you're in for a real treat!

 

[Wageslave]

Not sure if you would be able to control the fan? My buddy has a Trail Blazer SS and we replaced the clutch fan with electric ones from an 4 gen Camaro. The TBSS fan is a PVM fan controlled by the PCM. Here is a short description on what we found when doing things. When we installed the LS1 fans the tune needed to be changed from a PVM controlled fan to a normal electric output.

"As far as the voltage you are looking at, the PCM sends a Pulse Width Modulated (PWM) signal to the fan clutch relay (it's not really a relay, it is an electronic module) and the relay sends this variable signal to the fan clutch. The fan clutch a viscous clutch within it and that determines how much the clutch will engage. This PWM signal can not be measured with a voltmeter, only with an oscilloscope. The fan clutch does not start to engage until the coolant temperature has gone to around 230 - 240 degrees."

If the PWM signal is 0-12v DC square wave, it should at least give 0% or 100% lock. PWM fan controllers should give a workable approximation of that signal and make it work as a true PWM fan.

 

[Wageslave]

Wow so it engages when it is starting to overheat. As said, why would GM have wasted their time with this? If 12 volts turned it on and off sure, might work well, doesn't sound like that is the case.

It would explain why those Atlas engine's seemed to die an early death.