I have a 06 Dodge 3500 mega cab, Sat going down the road the air became warm. Blower still works but compressor does not engage. Dad has been checking wires & can't seem to get any voltage at the pressure switch or at the compressor. There should be voltage somewere down there shouldn't there? We've tried all of this with key on, a/c yellow light on, by the switch & blower on. I have a spare compressor & switch assembly. It acts as if i blowed a fuse, to the compressor, but the fuse panel is vague about if any of them are conected to the compressor. Any help would be appriciated. Thanks Chuck

 

Low refrigerant charge due to leak.

 

Ditto on the above post......very common problem. If that's not it, check the coil as they are prone to acting up as well.

 

Another vote for low freon. The low pressure switch will keep the compressor from engaging to avoid damage. You can "jump" the switch just to make sure there is no issue with the compressor but make sure you only leave it jumped for a short time.

 

The freon level is good, my dad has gauges. He has tried jumping it & nothing happened. He thinks the coils is burnt up in it, But he thinks ther should be voltage before the pressure switch, & can't get any. He thinks its the computer that is bolted to drivers side of the engine block. I have another computer & compressor we are gonna try it thurs. eve. Anyone ever heard of that causing thes kinds of problems? Thanks Chuck

 

Never heard of a trouble with the ECM (computer on the engine) causing trouble with the A/C. Usually it is the TIPM (what replaced the relay and fuse panel in the front Driver's corner of the engine bay. If the clutch coil on the compresor goes bad, the TIPM won't send the signal to start the A/C compressor. Some have been able to use a relay to send full independent 12v charge to the coil, instead of the juice coming from the TIPM. I just replaced my compressor clutch coil, and have good A/C again.

 

Could you explain more about the TIPM. Is it in the fuse panel? Something else besides the fuse panel? I need more specific info. Thanks Chuck

 

It's fixed! We changed the compressor, the coil is out of the old one. I was looking at the coils on e-bay & i have a question. the one i've been looking at has no terminal end on it, we would have to put our end on it. I was wondering if that is how it was on some of the ones i read about guys changing coils on here?

Thanks for all your help! Chuck

 

Chucka I pmed you, Did you receive it?

 

Yes, thanks alot!