PWM Cooling on a new LT4 Connect and Cruise build (1969 Camaro)?

[Bobsky]

Hi, Has anyone just wired in SPAL PWM fans instead of using the current GM Connect and Cruise relay controls (on/off)? I know I'd need to add in the temp sensor, but I've had the on/off control on other cars and hated it, while with the PWM, it's hard to tell when the fans are running... Unsure why GM made it so difficult to use modern fans.
:hand:

[raustinss]

Im 90 percent sure someone posted a thread about this with a solution. My brain is dumb I just can't remember who .. vapor works ??? Pardon me if im totally out to lunch

[dhutton]

I used Spal brushless fans on an LT build with the Spal controller that is available from Vintage Air or Wizard cooling. It is standalone and doesn’t interface with the ECM.
https://www.vintageair.com/instructions_pdf/113015.pdf

If you use brushed fans you can use Carls controller available from Northern Radiator on eBay.

https://www.ebay.com/itm/133436899126?hash=item1f11757f36:g:mOEAAOSwLN5e48q-

Don

[slammed68]

I've used this Derale pwm controller for fans in the past. https://derale.com/product-footer/electric-fans/fan-controllers/pwm-controller/16796-detail

Standalone unit that worked surprisingly well.

[John McIntire]

This can be done with the factory ECM that comes with the harness. You wouldn't need to run another temp sensor as it would just use the one currently on your engine.

There's a pretty big thread over on Lateral G that discusses this which is very educational. Search for a username "Mikels" who is Dave Mikels and he was actually a GM engineer that helped developed factory programming for production cars. He tunes Mark Stielows cars and can definitely get you set up to run PWM.

Good luck and let us know how you make out.

[dhutton]

I think you’ll need to tie in an AC pressure sensor to use the ECM if you have AC.

Maybe John Parsons will chime in since I think he has done it with an LS but not an LT afaik. It was pretty far from trivial if my memory serves me.

Don

[Bobsky]

Unless I hear another good option, I plan on going with a SPAL brushless (dual fan) design using their 215' sensor. It's a bit frustrating to not be able to use the E92 computer, but I also have high confidence in the SPAL brushless system to control cooling. I'm anticipating wiring in a trinary switch for a VA AC system.

[jasonz28camaro]

I think you’ll need to tie in an AC pressure sensor to use the ECM if you have AC.

Maybe John Parsons will chime in since I think he has done it with an LS but not an LT afaik. It was pretty far from trivial if my memory serves me.

Don


This is what I did on my LT but used a factory fan.