AC compressor questions, wiring
 

So when I bought my car it had working cold AC. It lost the refrigerant slowly over time due to a leak at the condenser. I have the compressor out to drain the oil so I know I will have the right amount when I go for a recharge. I lost an unknown amount of oil during my engine rebuild last summer.

Compressor on the left is an extra I picked up to get the correct 6 rib pulley. The compressor on the right was in the car and working. But it has an extra 4 pin connector that is melted and connected to something on the side of the compressor, RED circle. What does this do? It is absolutely necessary to have this connected? Maybe not to get the AC to work, but maybe to sense speed to shut the compressor off or something along those lines? Far fetched I know. :)

The chassis has a blue connector that plugs into the brown connector on the top of the compressor and a single blade to a ground or whatever.


https://cimg3.ibsrv.net/gimg/www.rx7...070f56e0c5.jpg


In this picture, you can see the extra 4 pin connector (red circle) and a repeat of the blue 2 pin and single blade (orange circle). Exactly what is on the chassis. Clearly it has been rigged to work in the past.


https://cimg4.ibsrv.net/gimg/www.rx7...9c3720ec31.jpg

I assume the car used to have a 4 pin connector at some point and it either broke or melted or whatever. My harness has been modded with an extra set of plugs to get it working at some other time.

The wiring harness on the car only has a one wire spade connector for the AC, that's it. I have not seen a compressor like that with the extra wiring.

On the back of the compressor should be a label, there are 2 versions, one for R-12 refrigerant and one for R-134a. Might be a difference there, I don't think I've physically seen the 134a compressor (it was only on '95 cars).

There is normally a short harness on the compressor that goes from the magnetic clutch on the front to the 2-wire connector on the top, then comes out to the one-wire connector.

Dale

Thanks, your response backs what I found out yesterday. I took it to my local AC shop and he indicated that it was prob a universal rebuild meant for another Mazda model (basically the wrong compressor for the RX7 technically). His Alldata system did not show any additional wiring for a speed/heat sensor as shown. Since my harness was in rough shape before IRP fixed it, I wasn't sure what it looked like to begin with.

I'm trying to reinstall my ac system too, but not cause it was leaking or anything; someone before me took it out for whatever reason (even though its not a track car and it's all black inside and out.) the connector you mentioned, the single wire, where does it plug into on the harness? im thinking the guy who removed it may have cut it off.. but the only wire I see close to the ac compressor that has been cut is black and red or brown stripe. but the one on my compressor is black with a white stripe. do u know? thanks.

There is a white plastic connector that outputs the black wire with the white stripe. There are two wires that feed into the back side of this connector...but I can't see on mine what color they are.

I can try and check mine as well. I lost track of which wire was which and asked IRP to get it connected for me when I had some other work done.

The single wire that was spliced and comes off my compressor connector traces back to a black with red stripe wire on the harness. Not sure if this helps you.