There's something up with my A/C. When sitting at idle, it works fine, but when I get moving down the road, it is worthless. It had enough freon, but was on the low end of good, so I recharged it with an auto store can this weekend, but that didn't help. Is there some kind of sensor or safety switch that could be killing it when I am driving?

 

We have several dudes here that are A/C techs...........one of em will check in with answers

 

Well, after testing a few different scenarios, here's what I have...

1) When I first start the truck and take off, I get cold A/C for about 5 minutes, then it is as if I shut the A/C off and am running just vent
2) When it is working, it works in both fresh-air and recirc mode.
3) When it is cold, it is cold on both L and R sides, so that doesn't seem to be the problem.
4) After the A/C dies, if I shut it (air) off for 5-10 minutes while going down the road, then turn it back on, it will work for a few minutes, then stop.

The A/C works, but something is causing it to shut itself off. I don't know if it is a sensor, preasure, freezing, or anything else. I ran a parts store recharge can with a guage. It was a little low, but not enough to make a difference so freon shouldn't be an issue.



A little update for tonight, I checked the codes tonight and saw a "P0647 A/C Clutch Relay Ctrl Circ Hi"

Could it be that at the higher rpm's the A/C clutch is still grabbing hard and turning too fast?

 

When you added the freon did you have a set of gauges hooked up so you could check the pressures? When you added the freon what the truck running with the A/C on? It kinda sounds like the high side pressure switch may be bad. If the system starts to build too much pressure it will shut the A/C off so the system won't rupture.

Another thought, is your can clutch engaging when the A/C is on? If not this could be the problem as well. What the A/C is on the fan clutch should engage. This makes the fan work so it pull air across the accumulator which keeps the pressure from building too high within the system.

 

my ex had a problem with the vaccum sensor/pump( whichever they have it was a year ago) in his dodge that caused the a/c to not work properly ( also the 4wd would not work) but he totally broke his maybe urs if you have one is just malfuntioning? it was broken during the installation of his edge chip believe it or not which the people who did it said wasnt possible. im not sure if it applies as his was a 2nd gen, but i thought i would mention it just in case, i culd be totally off base but if i mite have given an idea i thought what the heck . ne ways hope u get it figured out.

 

If I recall, on the 3rd gen trucks, Chrysler got away from vacuum actuators? Everything is electrical.

 

i thought sumthing lke that might have happened but i thought id mention it any ways, sry guys.

 

I did have a guage on the freon can, with the A/C running on max when I put it in. I ran it up to the high end of the "OK" mark, so it shouldn't have too much in there.

I don't recall if the fan kicked in or not. I can feel the compressor kick in, but once it shuts off, it doesn't come back unless I turn the A/C off for a few minutes.

 

i have a similar problem with the ac unit on my 06 cummins, the ac works great while im driving my truck but at an idle i have no ac. the fan kicks on but will I will have nothing but hot air blowing out of the vents, anyone have any ideas?

 

It sounds like an electronic problem on your 06. In 06 chrysler went to a CAN-BUS system. Everything is tied in.