2001 Chevrolet Silverado e-fan swap

[Life is an Enigma]

[Life is an Enigma]

I mean I started with the standard gm e-fan schematic diagram, but I added a 4th relay to accomplish what I want.

It's a 2000, so it definitely didn't come with the pressure sensor. They started putting those on the trucks in 2003.

99-02 AC Compressor Clutch Control

Okay, your system is set up with a two-wire high pressure and low cycling pressure switch. In your tune under AC systems under hardware under type fitted do not touch it. It's set fine for your AC system. The diagram I posted above was the two diodes will do the same thing as a relay. It will override the high speed fan turn on when the clutch for the AC compressor engages. Only thing you're going to be doing with a relay is taking a positive trigger and turning it back into a negative trigger to turn on the high speed fan. The diodes is just an easier way to do it and takes up less room. Basically, what you're doing with the diodes is isolating pin 43 from pin 33 so there's no back feed in the ECM. Pin 43 is negative trigger for the AC relay to turn on the pump. So when the pump comes on it will override the pin 33 negative trigger and turn on the high speed fans.
Screenshot (800).png

[07sgguy]

Okay, your system is set up with a two-wire high pressure and low cycling pressure switch. In your tune under AC systems under hardware under type fitted do not touch it. It's set fine for your AC system. The diagram I posted above was the two diodes will do the same thing as a relay. It will override the high speed fan turn on when the clutch for the AC compressor engages. Only thing you're going to be doing with a relay is taking a positive trigger and turning it back into a negative trigger to turn on the high speed fan. The diodes is just an easier way to do it and takes up less room. Basically, what you're doing with the diodes is isolating pin 43 from pin 33 so there's no back feed in the ECM. Pin 43 is negative trigger for the AC relay to turn on the pump. So when the pump comes on it will override the pin 33 negative trigger and turn on the high speed fans.
Screenshot (800).png

Oh I'm aware, thanks... I'm not OP. I was just contributing a different solution that happens to work on my vehicle.