98 LeSaber. Want to jumper a/c switch to test

Behind the compressor is what looks like the drier and the pressure switch. I would like to jumper it so I can see if that is why may A/C is not working. The clutch will not spin when the a/c button is pushed. I also noticed the pressure switch is a three prong connector. Which do I jumper.

Hello

Good queston! I would becareful here. If your heat/ac is controled by a computer, sending power down the wrong wire might fry something. Don't guess here. Make sure you have a "good" wiring diagram before moving foward. By the way, you should be able to remove the switch without loosing 134a. There should be a valve under the switch.

Dan

Unless you've confirmed the pressure swtich is defective, the best thing to do is check the charge on the low pressure port. If low based on the ambient temperature add R134a in 4 ounce increments to bring the charge up and then then see if the compressor starts cycling.

On the 3 wire pressure switches I agree you have to be very careful jumping it. One wire is a ground. The other two are a reference voltage of less than 5 volts from the PCM module and a signal line going back to the PCM module. The other thing to note is that it is both a low and high pressure switch. To do a proper jumper you'll need to insert a resistor of value that will represent normal pressure so the compressor operates correctly. All a straight jumper will do is pass the PCM reference voltage to the PCM. The PCM will detect high pressure and you'll be back to square one...which is no compressor turn on.