Ando427

Hey guys, I recently bought a 2007 Dodge Ram 3500 4x4 SRW Quad cab with the 6.7L Cummins and it turns out the A/C is not working. I thought maybe it just needed a recharge so I bought a can of refrigerant, but when I checked the pressure, it read high, with the needle pegged to the far right. Thinking that maybe someone had tried to recharge it in the past and over pressurized it, I released pressure from the low side valve until the gage read in the normal zone, but still no cold air.
I noticed that the compressor makes a rattling sound every so often, as if it is trying to engage, but it does not seem to actually be engaging. At this point I'm thinking something is broken in the compressor and I should probably just replace the whole thing. Am I on the right path here?
Thanks for your help!

shep1

I thought the same thing about mine. did some "RESEARCH" on here and discovered the recirc door, located behind the blower motor, had broken and fallen down blocking air flow across cooling coil. I remove the glove box, remove the blower motor and reached in and checked to see if this was the problem. It was. I removed the broken recirc door and reassembled all. Cooling worked as good as ever. I just can't change from outside air flow to recirc air flow. It has been working fine this way, haven't had any problems. Always remember to lower or turn off fan before changing any air flow settings, then bring fan speed up slowly. One step at a time. It seems that higher air flow tends to push the flap doors to hard breaking the plastic drive couplings that turn them. Hope this helps. Not sure about compressor issue.

Ando427

Thanks for the response Shep1. I did some reading on the recirc door issue, and it looks like that causes low air flow, even when fan speed is set to high. I'm able to get air blowing out of my vents at all different speeds, so I don't think this is the problem.
I also looked into the blend door problem. From what I can tell reading on here, the blend door blends different temperature air so you can adjust between hot and cold. I'm also able to do this without a problem. I can turn it to full hot and get very hot air, or turn it colder and get air that will get as cold as the ambient outside temperature. My problem is that even after pushing the AC button, I do not get colder than ambient (or refrigerated) air.
So I guess at this point I'm still thinking that the issue resides with the compressor.

Mexstan

This may appear to be a bit of a stupid question, but is the compressor clutch actually engaging? Have you looked to see that the compressor itself is turning?