A/C Help!!! Sanden 508 wiring

[hydrospec2001]

Hi yall! I recently joined the site and have seen some beautiful trucks on here and eventually hope to get around to posting some pics of my baby as well. Also I hope to gain some knowledge as well as try to help as much as possible. Anyway, I've seen a few threads on here with people that have changed their A/C compressor from the pancake style to a Sanden 508. The question I have is the wiring. The 508 is a one wire compressor and the pancake style had two wires. There is a light green wire and a dark green wire. Both wires come from the cycling/pressure switch and I know the light green wire is hot from the climate control switch in the cab. Where and how do I wire the compressor. I was assuming the dark green wire would be the wire to the compressor but when I run a test light to the dark green wire off the cycling switch I have no power. It is a new cycling switch. If I run the light green wire to the compressor it will engage the compressor but how will it cycle on and off. I'm afraid of burning it up. Could somebody please tell me how to wire this thing up!!! I live in AZ and cold air is a necessity. Any help sure would be appreciated. Thanks so much!

[jjzepplin]

Alrighty so welcome to the forum and I think we can get this worked out for you. Is this the original wiring going to the old compressor? Normally the hot wire will go through a cycling switch and then just one wire to the Sanden. The switch will turn on the compressor and cycle it when there is enough pressure and then shut it down automatically.

[hydrospec2001]

Hi! Yes it is the original wiring. The old way it was set up was it had a plug that went into the old compressor. A light green wire that went from the climate control in the cab to the cycling switch. From there it went over to the compressor and then it was doubled so it could also go to the fast idle solenoid. The dark green wire only came off the cycling switch and went over to the same plug as the light green wire and both plugged into the compressor.

[jjzepplin]

Sounds like one wire was a ground.

[pontgta]

One wire should be be going to pressure switch ant the other to ground....

Take alook at this..





Found here http://forum.73-87chevytrucks.com/sm...?topic=18143.0

[hydrospec2001]

Ok! That would make sense if it is. I have some time off work today so I'll go out there and test it to see if it is. I will post back what happens. Thanks!!!