Ninety-One

My a/c compressor on my iroc was leaking out the whole rear of the unit, so I switched it out to a brand new one I had on a 91 305 tbi sitting around. Now everything matches up the same, except the a/c clutch plug. The plug on my car has a 2 prong with a resistor jumping across the two contacts. I found online the correct plug for this "newer" 1991 style compressor, but I am wondering if I must keep the resistor in the circuit when I splice in the new plug? I have some pictures...

Ninety-One

Here is the resistor in line....

jermdm

Its actually a diode, not a resistor. And yes, you have to have it wired in. The diode will only allow current to go one way so make sure you splice it in correctly. I think its there to prevent voltage spikes when the clutch engages. My diode went bad a while back and the compressor clutch wouldn't work till I replaced it.

Ninety-One

Thanks for the reply jermdm, I really appreciate it! Will splice The "diode" in. Sorry for my ignorance. It's starting to heat up here in Cali and it's time to convert to r-134a.

Thanks
Brendan

Lurbie

iTrader: (3)

Yes that's right it's a diode, but it is actually there for when the compressor shuts off. When the clutch is disengaged a very large electrical surge would go back through the wires and into the electrical system, this diode allows the electrical field to collapse back through the clutch windings. I don't see how it would have kept your clutch from working, unless it was shorted at which point the fuse would likely blow.

jermdm

Hey lurbie. I didn't have any electrical shorts or anything to keep my clutch from engaging. When I was trying to get my ac working a while back, I went thru everything(electrically and mechanically) and everything checking out ok but the clutch still wouldn't engage. I was like, this should be working but it wasn't. I could apply voltage to the clutch and it would engage but it wouldn't work thru the HVAC system. Just about gave up and decieded to check the diode since it was the only thing left I hadn't checked. I cut it out and checked it and I had continuity going both directions on the diode. Should have continuity only going one direction. Got a new diode and as soon as I slid it in the connector, boom, clutch turned on. So just from my experience, the diode is needed for the clutch to engage.