Your low pressure switch should be located on top of the dryer. It's a silver looking canister on the passenger side near the firewall. I'm uploading pics now
Here's the two wire switch Here is the canister I was talking about Unplug the sensor and take a small piece of wire to stick into the pins. Turn the ac on and see if compressor kicks on. If it does then it's low on freon. If not the there is other issues.
didnt get chance to look at the ac like i wanted to....everyone at work is telling me to just buy they recharging kits from napa or whatever...im afraid that i will overfill and mess up the compressor...anyone try these before...i know you can get gauges that prevent one from overfilling...im pretty picky about my truck and dont usually work on stuff like this myself...local guy wants 68 to diagnos and then another 130 to recharge if neccessary! f that noise!
YouTube - How to re-gas the air conditioning in your vehicle‏ here's a great you tube video that will help you. recharging is fairly easy