Hi I'm new around here. First post..
I have problem I'm trying to figure out.
I have a 2001 dodge ram 5.9l v8. And the A.c. didn't work so I went to charge the system but the seals on suction and discharge manifold was leaking bad so I couldn't. But i thought I would test the compressor by jumping to see if it would kick on with no luck. So I tried probing all the connections and can't find power on any. The low pressure switch has nothing and the switch on the suction discharge line also has no power.
I checked the fuse and it's ok and switched the relay and nothing.
Am I missing something. Need some help. Thanks in advance.

 

Did you have the controls set so it would actually WANT to run the compressor? Fan needs to be on as well......

You can get a service manual here, wiring diagrams are in section 8W.

 

I have it set to max a.c.. fan is blowing hot air. Just no power to the low or compressor I even tried to jumper the low switch but with no power it was as expected nothing. I look over the wiring diagram. Thanks
And ​​​​​​I just wanted to see if the compressor worked

 

I *think* that the control circuit thru the high/low pressure switches just control a relay in the PDC, and the relay is what sends power to the compressor. If you don't have power on the control circuit, need to find out why.

 

I'm getting power at the relay could it be a head unit in the dash

 

You should have power to turn on the relay and power to supply the compressor when the relay activates. Look at the wiring diagram it will show you how they are running the wiring for it and the high/low pressure switches.