A guy I know is building a street rod and has a 5.3 out of a 2003 or so chevy pickup (drive by wire) and he was checking to see if the clutch on the AC pump kicked in and he hooked juice to it and it did nothing. This is the plug that is up by the clutch. I noticed that there is a plug on the rear of the unit with some wires, Not sure if maybe this needs 12v to it someplace or not, Just trying to figure out how to get the clutch to kick in. He is using an aftermarket AC system and I believe it just has a hot trigger wire for the clutch.

Anybody know what al the wires are for on the AC pump?

Thanks.

Lance

 

It's PCM Controlled. The over all logic in the system works like so:

PCM receives A/C Signal request from you pushing a button. PCM Checks engine RPM and A/C Line pressure, if both fall within spec then it sends the signal to engage the clutch.

 

Thank you.

Any way I can override it to work with just an on/off switch? (with a pressure switch in-line)

LK

 

http://www.thirdgen.org/techboard/lt...ng-i-need.html

Ground the relay and the compressor clutch will engage

 

Shouldn't I be able to put 12v to the clutch plug and hear it click? (it does not) I thought the plug on the rear of the compressor might need some voltage also? Any ideas. I looked at the wiring diagrams listed and it looks like they just have voltage to the clutch wires. Does it send a full 12v to the clutch? I also have another 5.3 on a stand and I tried that one also and the same thing, Nothing. Any idea what the plug on the rear of the compressor is for?

LK

 

I'm not sure about the rear plug but the the clutch wiring goes like this A 12v+ B 12- and the factory wiring has a flyback diode across A to B so as power is removed the 1100 or so volts that is produced in the clutch as the magnetic field colaspes has someplace to go. Without the diode the clutch will be toast after a some use and other electrical components my fail.