not naer my manual right now, but IIRC most of the realys are behind the glove box area, but you should not mess with those without the EWD, you could try the pressure switch right now without an EWD as it simple and only has 2 wires, on my 96 the pressre switch is just infront of the batery behind the headlights. it is a bulbus looking thing with wrench flats that is threaded into a fitting in the middle of an aluminum refrigerant tube with a 2 wire bundle going to it, release the clip and take the plug off the switch, best would be to make a short jumper by crimping 2 blade terminals on a 6 inch or so piece of wire, or you could do it the red neck way and just strip a piece of wire and stuff the bare ends into the plug, inset both ends of the jumper into the bundle side of the clip, the pressure switch is now out of thr loop the truck thinks the pressure is OK, the compressor will run no matter if the pressure is to high or to low, have an assistant get in start the engine turn the ac on in park, you watch the compressor, the center of the ac clutch should start turning have the assistant put the truck in gear if the comopressor still cuts out the pressure switch is not your problem. call Cdan and order the EWD for further troubleshooting, if it does not cut out in gear then than:
A the pressure is to low or to high, there is to much or to little refrigerant in the system, sease operating it as this can kill the compressor, have it propperly serviced (more likely)
b the switch is bad (less likely)
