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mikle3005 · Jun 18, 2009, 03:00 PM

My a/c clutch is not engageing due to no power caused by that little switch that shuts it off I stuck a paper clip in the switch and the clutch engaed I bought a diy recharge kit and hooked it to the low pressure side, when I hooked it on with everything up and running it did not show a pressure on the gauge, I squeezed the triger for aprox 10 sec's let off and the needle was in the red?? Any advice would be great!!

TxGreaseMonkey · Jun 18, 2009, 05:33 PM

To me, it sounds like there's a major leak. The first order of business, then, is to locate and repair the leak. If it's unclear where the leak is, get help identifying it. Afterwards, you may be able to replace many of the parts yourself, have the system evacuated, leak tested, and recharged. Here's my recent experience, which I hope gives you confidence to properly solve the problem yourself:

https://www.askmehelpdesk.com/cars-t...ml#post1722090

With all of the room under the hood in a Dodge Ram, it should be a lot easier to work on than my Taurus with a Duratec engine. If I can do it, so can you. A/C repair work is not as hard as some make it out to be. If you replace the compressor/clutch assembly, accumulator, and orifice tube, you'll have pretty much have a new A/C system.

mikle3005 · Jun 18, 2009, 05:53 PM

How would a major leek cause high pressure, how would I find a leek if the system won't suck in the freon, I've got a uv light, is it posible that the system is just low and valve on the low side is stuck shut

mikle3005 · Jun 18, 2009, 06:02 PM

I'm told it's the low freon shut off switch it's a green plug wtb two wires comeing out of it the two I cross wired to get the clutch to engage it sits ontop of a cylender that the low side line runs Into

TxGreaseMonkey · Jun 18, 2009, 06:23 PM

Are you referring to the A/C Low Pressure Cut-off Switch?

My take was that the pressure, for whatever reason, dropped so low that the compressor won't engage. Low freon levels prevent the refrigerant oil from properly lubricating the compressor, so the PCM protects the compressor by preventing it from running.

mikle3005 · Jun 18, 2009, 06:44 PM

I'm told it's the low pressure cut off switch I'f you have an email I can send you a picture of it then were both on the same page for sure

TxGreaseMonkey · Jun 19, 2009, 05:38 AM

If you jump the A/C Low Pressure Cut-off Switch, the A/C compressor should kick on. If it does, there is something wrong with the A/C system--probably not enough refrigerant. Hence, I suspect a leak.

My advice is to stay away from DIY recharge kits. It's best to use a CoolTech machine; otherwise, use a two-hose manifold gauge set, with can tap, and vacuum pump. A two-hose manifold gauge set allows you to monitor the high and low pressure side of the system simultaneously, as freon is being added.

You never told us the year and mileage on the truck.

Since freon is the PAG oil's carrier, look for evidence of oil, especially around the compressor. Most major leaks are compressor-related. Also, check the condenser coil for puncture--stones are a common culprit.

octavianv · Jul 28, 2009, 04:24 PM

I have a 2007 Dodge 3500 6.7

The A/C was running yesterday morning when I left the truck running at a job site for about 1 hour, of which worked properly, then all of a sudden quit blowing cold. I have looked for a relay or fuse that may have burned out but cannot locate a relay. Compressor does not come on. Please help!

TxGreaseMonkey · Jul 28, 2009, 06:51 PM

octavianv, see if the link below helps:

https://www.askmehelpdesk.com/cars-t...ml#post1864159

chubby1432 · May 3, 2012, 06:35 PM

My a/c only blows on my feet. The a/c nob on the dash can be on any position but still only blows on my feet. It makes a thumping sound under the dash like its trying to change but does not. Any help would be great