I turned-on the a/c in my '06 RAM quad cab today to find that the air coming out of the vents got no cooler at all. The a/c worked fine last weekend.
When I turn the fan on to any speed and press the a/c button, the button lights-up but I cannot hear the a/c compressor engage. No clicking or and different sounds at all.
I have seen LOTS of post about a/c on the forum. The truck only has 39k miles on it and the a/c worked fine last weekend so I'm hoping it is not the compressor.
Is there a fuse, relay or switch that would cause this symptom? If anyone has any thoughts, please pass along before I have to take it to the dealer? I appreciate the input. Phillip

 

low refridgerant will cause the compressor to not engage. keeps it from burning itself up. get a a/c servicing unit on it, vacuum it down, add dye and recharge.

 

I read this on another forum and found it of much interest as I did change my oil over the weekend: "had the same prob with no a/c. turned out to be a loose connection in the wiring harness plug at the compressor. my wires get pushed around every time i change my oil filter so they're susceptible to damage"
Anyone have any thoughts on that one. I cannot check the wiring until tomorrow. Thanks, Phillip

 

Oh, well. I got a chance tonight to check the wiring and it all is in tact and there does not seem to be a problem with it.
There are no fuses or relays under the hood for the a/c - at lease none labeled as such.
My next check will be to have the refrigerant checked. phillip

 

Turns out the problem in my case is the evaporator coil. Had it replaced today by the dealer. Now, just in time for the FL heat, the a/c is ice cold. pcm