Having some AC issues, thought it might be the compressor but not so sure now. All of the fuses and relays are working however clutch doesn't engage. The wiring harness that connects to the compressor does not show any voltage on a meter. We tried jumping the pressure switch to engage the clutch but it just caused the vehicle to die! Where does the harness get its power from? And how much voltage should this be reading? Any other ideas about what the problem might be or where to look next?

 

I'm beginning to wonder if my system has a traditional low pressure switch. Aside from the actual wiring harness to the compressor, the only other switch is coming off of the condensing unit. It has 4 ports and doesn't seem like a low pressure switch I've heard described. Which is probably why it killed the vehicle when we tried to jump it. Can anyone tell me where the low pressure switch is? Or if my model has one? 2003 Durango SLT 4.7L