Greetings! I recently bought a running 86 Nissan 720 Reg Cab Base Model, carbureted Z24 with 197K, 5 sp MT 2WD. Drove it home. Tested the A/C and I hear the compressor kick in but of course - no cold air. It has never been converted from R12 to 134A. I have looked everywhere and have failed to identify the Low and High pressure access ports. Where could they be? Any help would be appreciated.

My factory service manual should arrive in the mail soon, but this really has me stumped!

If you are having difficulty in even locating the ports, you should not even touch the AC system............ as A DO-IT- YORSELFER you dont have access to R12 to refill anyway, and a conversion to r134 requires alot more than just pumping it in..... TAKE it to a professional for testing and repair!!

I found the ports. They are located on the compressor itself. Never saw a setup like that before. Always were in-line on the hoses. Thanks for the advice.

I have seen other Nissan 720 trucks but I have never seen ports coming straight out of the compressor. Here is a photo of my compressor, The ports are on the end towards the firewall, very hard to see from above. This photo is taken from the drivers side wheel well.

Next question: Why can't I use a retrofit kit and charge my system with 134A? Maybe you think I'm stupid, but I just don't know why I couldn't do that.