Cooling Fan relay setup

[fauXGT]

When I eliminated the clutched fan on the '91 GT for intercooler piping, I researched alot of junkyard parts. I realized that there is alot of confusing ways to go. Being my ECU does not have signaling outputs for e fans, I went for a single SPAL 16" fan with a variable speed controller. Has an A/C auto on input and a stand alone temp probe that fits into the radiator, being I'm running a 180* thermostsat for the supercharger. It doesn't matter what temp anything else is running, it only kicks the fan on when it needs to. Hot days when shutting it off, the fan will still continue to run for 30+ seconds after just to cool things down, then turn off. It does vary the speed... not just low/high. 15 years ago $110 for the fan and $80 for the controller/temp sensor. Love it. My 2 cents.

[57FleetsideC4]

Originally Posted by fauXGT

When I eliminated the clutched fan on the '91 GT for intercooler piping, I researched alot of junkyard parts. I realized that there is alot of confusing ways to go. Being my ECU does not have signaling outputs for e fans, I went for a single SPAL 16" fan with a variable speed controller. Has an A/C auto on input and a stand alone temp probe that fits into the radiator, being I'm running a 180* thermostsat for the supercharger. It doesn't matter what temp anything else is running, it only kicks the fan on when it needs to. Hot days when shutting it off, the fan will still continue to run for 30+ seconds after just to cool things down, then turn off. It does vary the speed... not just low/high. 15 years ago $110 for the fan and $80 for the controller/temp sensor. Love it. My 2 cents.

Thank You for your opinion on this. My goal is to let my PCM control the fans. I am just looking for a way to let the PCM know the A/C is on which is a Vintage Air Gen IV system. I have a A/C request wire just need to figure out how to use it. Steve

[Hcb3200]

What version of PCM are you running?
Or ECM e38? or something else

and I just realized you could run a PWM (pulse modulator)
GM/crysler/generic has them for single fans to control the speed as needed.
It can wire directly to most ECM modules and do what your asking nice and clean.

search for your model of ECM add PWM and fan wiring and a lot of sites especially on LS swap sites have all the pins wires you need.
You don't even need the fancy expensive corvette model there are some basic ones that work well .

[57FleetsideC4]

Originally Posted by Hcb3200

What version of PCM are you running?
Or ECM e38? or something else

and I just realized you could run a PWM (pulse modulator)
GM/crysler/generic has them for single fans to control the speed as needed.
It can wire directly to most ECM modules and do what your asking nice and clean.

search for your model of ECM add PWM and fan wiring and a lot of sites especially on LS swap sites have all the pins wires you need.
You don't even need the fancy expensive corvette model there are some basic ones that work well .

I think is a 411 it is the stock unit used on 05-06 silverado. I am trying not to add any other controllers just let the stock pcm do what it needs. Thanks Steve