Hello all,

I was finishing up my LS swap for my 87 IROC…





I got a Holley mid mount accessory kit. It comes with a Sanden SD7 A/C compressor that has only one wire for the clutch… see pic. Anyone know the connection type name/size?




I’m using the harness out of a 4th gen. There are 2 wires that go to the 4th compressor with the colors being green and black.

When I went to keep the green wire, I noticed the black ground wire is spliced into the green (see pic). It also connects to the ground too. I cut the green wire that was coming from the relay as my A/C clutch wire… was that the right move to make? Thanks in advance.

 

The compressor connection is just a bullet type. You can get them at any parts store. The kits will come with both female and male ends.

 

There is a diode inside that heat shrink. Leave it there like factory.

 

My compressor is a single wire. I cut it out… but I kept it in case…

what does the diode do in this circuit?

 

I dont know if its absolutely necessary so you could wire without it. I heard it was used to keep the relay from chattering as it cycles on and off but Im not sure. I left it in my harness so I wouldn't have any issues

 

Thank you so much. I’ll try without and update here. Again, thank you.

 

The diode acts as a "snubber" to keep the flyback from the relay, when the contacts open, from arcing the contacts over. Without it, the relay will enjoy early retirement.

The old R-4 clutch was isolated from ground, and therefore required an external (wire) connection to ground, on one end. The other end of course is the "hot" and gets 12V from all the control circuitry. The Sanden has one end of its clutch already grounded, therefore doesn't need the black wire.

Not sure what Skillet was doing with that harness in that pic. That can't possibly work under any circumstances. As is typical of most "improvements" people make to their wiring... if they understood basic electricity, their harness would work just fine without ANY "improvements".

Cut the green wire off right behind the OE connector; undo the sodomy involving the black wire; do away with the 2nd green wire; assure that the remaining green wire goes to where it needs to go; put a bullet on the end of it and plug it in. If you can get an insulated one that would be best. Not hard to find those at the junkyard.

The diode though, needs to be grounded. It needs the end with the band connected to the clutch, and the other end grounded. Check that black wire and see if it's still hooked to the diode, or if it can be put back: without that, the diode can't fulfill its purpose of keeping the relay on the job.