Hello,
Haven't been on here too often, no need, just enjoying my 06 Dually Mega.

But now the ac has quit. Looks like the compressor is not engaging...or the clutch isn't. Its below the alternator, right? The vehicle has 60000 on it, just barely so I'm not sure why this issue is coming up.

On another site, they talk about the compressor and something called a TIPM...Is there any write up somewhere that describes the procedure to go through checking this issue? I'm getting warm air blowing through so I don't think its that vent door issue.

I searched and found some guy had asked about a low pressure switch. 60plus views but not one response. Is this topic too arcane or its just something that no one knows how to fix?

RW

 

Viewer # 61 response:

Have you inspected the system for leaks? Trace each and every hose (then the condenser as well - sometimes a rock can take out a tube). look for refrigerant oil it is the only clean oil on these units

Was it working good then just quite or did it die a gradual death?

 

Wow, thanks for the response. No oil is apparent on any lines. Is the compressor the one below the alternator? Otherwise I think I'm looking at the other side and the fuel injection pump is on that side with the power steering pump. I think!

The system was working one day, not the other. I wasn't home, but that is from what I gather. I don't see the clutch moving at all at least on the item below the alternator which looks like a compressor. Thoughts?

 

Yes the compressor is under the alternator, it is best viewed from the bottom up. check the electrical connector to the A/C compressor to make sure it is pushed together all of the way (mine came apart when I drove though some weeds once.) The low pressure cut-out switch is attached to the line above the compressor..

There is a wire chaffing problem associated with this generation of truck make sure the wire has not worn through the insulation from rubbing on the aluminum lines. I covered mine with a split wire loom to prevent this. All of the flanges (lines to pump and condenser has o-rings in them be sure to check it out thoroughly..

If all checks out and it still don't work try taking off the connector to the low pressure cut-out switch and put a jumper wire in it(that's how you energize the system to charge it), if the clutch kicks in you need some freon and a leak will probably show up somewhere in the system..

Hope this helps..

 

WOW, great advice, thank you. Will try those fixes tomorrow and see in the daylight.

Can you tell me also where the low pressure cut out switch is located?

I've also done some more research and one of the issues with the compressor is that there is some sort of magnet in it. If the clutch and magnet get worn, they separate in terms of space, causing the compressor to be replaced...bottom line. Does this make sense on a 60000 mile vehicle?

 

OK, found the low pressure switch. There's another posting where someone puts up a factory schematic of it.

When jumping the switch, I'm somewhat confused to going to basics...I stripped some wire and put it into the female end of the electrical connection, that side that goes to the harness. Nothing happened.

I'm wondering if I'm supposed to jump the switch on the male side, that is the part attached to the ac pipe? If so, how can you see what you're doing, the fenderwell is in the way...do you remove the inner fender plastic to see or just shove the wires in hoping they make contact? (I did this but again, the clutch did not come on.) You can't see the inside of the switch with those tiny electrical spades...

 

You did right on the connector not the pipe side.. Was there a 12V signal at that point?

 

I'll have to go back out. I just took a piece of wire and stripped off the insulation, put it into the terminals of the plug. The clutch did not come on.

There are three terminals on the plug though a fourth is built in but empty. Any idea which I should test...using a light or a multimeter?

You might see I'm not the most experienced by my questions...thanks for hanging in there.

 

A test light or multimeter will do.. I just looked at mine the red should be the hot one..

If you have a multimeter check what terminals are communicating on the switch (attached to the line)

Also have you checked the fuses? my 05 shows a fuse for the A/C clutch relay

 

I don't know how to interpret these results at all...

1. With a working test light (tested on the battery), I got no light on any of the terminals...but, there was a noise, like a flapper door or something opening, when I put the test light probe in any of the three terminals. It would make a noise like twice on each terminal.

2. With a multimeter, battery showing at 14 something, in one of the terminals, the reading was 4.93. The other terminals showed 0.00.

Checked fuses, under the hood, right, passenger side? All seemed to be in order that had anything to do with HVAC. There is also no specified AC clutch fuse.

 

Fuse box is drivers side.. check them with the light as some of them can be hard to see when their blown. sounds like you might have TIPM problems.. which is a dealer only reset / repair

 

I don't have an AC clutch fuse though. Does all the information about the plug tell you that its not the compressor?

 

No fuse A/C related? My 05 has both a fuse that says A/C clutch and a Clutch relay as well... sorry I'm not more help you might be stuck with a trip to the dealer..

Maybe someone with an 06 will chime in..

 

ONly one fuse indicates HVAC and it is working. Its got other things tied to it too. Checked the owners manual to confirm.

I appreciate the help. AC help is few and far between due to the black magic aspect of it. Thanks!!

Ralf

 

Got the TIPM, my dealer told me I got it cheaper than he could get them for and I got it from a Chrysler dealer.

Anyway, it should be installed today, they told me .5 hours for the install and electronic adjustments. That should cure the AC clutch problem as it goes through the TIPM which was exhibiting other issues as well, such as making door locks inoperative and putting the drive train in neutral through the 4x4 switch. At least that's what the mechanic at the dealership surmised.