I posted this in the performance forum by accident and wanted to re post in the correct place. Sorry about that.

I have a 2007 Dodge 2500 w/ the 5.9L that is having AC issues. Yesterday the everything worked fine and today nothing. I turn it on and the clutch on the compressor is not engaging. I checked for leaks, and the system has 100 lbs on the high and low side w/ the compressor off obviously.

I checked the voltages on the terminal that plugs into the pressure switch and I am showing 5 volts when I have the AC button engaged and off. From reading an old post Madhat it looked like the pressure switch does operate b/t .451 to 4.519 volts. Here is the a partial quote from his post:

For the air conditioning system to operate,
an A/C pressure transducer voltage reading between
0.451 and 4.519 volts is required. Voltages outside
this range indicate a low or high refrigerant system
pressure condition to the Powertrain Control Module
(PCM) or Engine Control Module (ECM) depending
on engine application. The PCM/ECM is programmed
to respond to a low or high refrigerant system pressure
by suppressing operation of the compressor.
Refer to the A/C Pressure Transducer Voltage chart
for the possible conditions indicated by the transducer
voltage reading.

So how do I find this A?C Pressure Transducer Voltage Chart or a wiring diagram for the HVAC system on this pickup? Thanks for the help folks!

 

Hmmmm....Madhat any input on this? I'm sure some others might be wondering the same thing. Thank goodness my '03 has had most of the a/c system replaced by yours truly and blowing extremely cold.....oh, wait, this thread was on how to just get the thing work .....Madhat...anyone???