Thread: Where is A/C pressure switch?

Anyone know where the A/C pressure switch is on a 1997 GP? My freon is low and the A/C comp. wont cycle for my pal to charge it. (It has some in it yet) Anyhow, he says we need to unplug the pressure switch and/ or jumper it so the compressor can run to charge it. We looked all over and could not find it.

There is a pressure switch that's under the airbox on the driver's side. IIRC it's the cycling switch.

I had the exact same problem, but I improvised after looking for what seemed like days.

1. Pull the A/C clutch relay out of the fuse box in the wheel well.

2. Take a switch (or a wire lead if you don't have a switch).

3. Run it across the pins which are completed when the normal switch would close the relay. (I believe it is 1 & 3, but I am not at home right now to check my notes. Look on the side of the relay for the schematic. It is a normal X-over relay.)

4. Be aware, A/C clutch will kick in the whole time you have the wire bridged between connections. Make sure you are ready to go, and have an assistant bridge the pins while you work the can.

WARNING: Make sure your system has NO leaks, as the compressor will ramp up the PSI on the High Side very very quickly (and if you don't have your can hooked and ready, normal air will be compressed). Don't risk blowing a pipe and hurting yourself or someone else.

I found the high side line pressure switch. It is a 3 prong connector. Does anyone know which need jumpered for the compressor to run?

I got it done today. I jumpered the realay like StreetChariot sad to get the charge going high enough that I could then plug the pressure switch back in and it would let the comp. run. One note about jumping the relay only is it does not trigger the fans and witht eh fans not taking the heat off the condenser the high side pressure comes up pretty fast. So I would not advise doing this for much more than getting enough charge in for the switch to take over. Thanks.