Hello, I was browsing other posts and could not find any with an answer to my question so im posting it her hoping someone might have an idea where to start. I have a 1990 Daihatsu Hijet S83p with Air Conditioning. When i got it last year it was cool outside and i never tested AC. I attempted this summer and it did not work. I did not look into it much at that time and just recently started looking at it but do not know what really to look for. But basically nothing happens when you turn the cooler box inside to the coldest setting, the AC compressor does not come on, and no cold air. Things i did so far. Disconnected the wire going to the AC Compressor front and reconnected it, took out the cooler fuse and relay right next to it to make sure they were good. Reached behind the cooler box in the center of the cab and disconnected the wire and re-connected it and checked for voltage (got no voltage) . I do not have a gauge to check the refrigerant PSI , however i did just quick press the pin to make sure something was there and did get a hiss for a second. What I am confused about is that it appears that the body of the Hijet is not ground. When i test from the battery positive to the screw terminal on the front of the AC compressor it is at 12-14volts however i would expect the body to be ground and the screw terminal to be hot to turn on / off the compressor. Then also when i touch the positive battery to anywhere else on the engine i also get voltage. So i am confused it appears to be positive ground. I would have expected that the screw terminal on the front was the way that the magnet clutch engaged by energizing, but with it always being positive even when all the fan and air con is off, i have second guessed myself. I was wondering what to check for next. Maybe someone has some ideas for me. As always, thanks for your time and i look forward to reading the replies.