AC keeps freezing up! HELP PLEASE!!

2005 dodge 3500 cummins

Accumulator bottle freezes up

no cold air out of vents

new compressor and recent evap core replaced

I am changing the lines tomorrow including the orrifice tube, also changing the ac circuit breaker just in case..

The compressor kicks on as soon as you turn the AC on....even with the 134 evacuated! I know this cannot be right


Any help would be greatly appriciated.

COLT

If the compressor is kicking on even with no freon in it, something is telling the hvac controller or body control module that the conditions haven't been me tto cycle the compressor off. A pressure switch or like a evap temp sensor issue. But it would cool with freon in it right untill it froze up when it should cycle off? I say take it too a dealer and pay the diag. With their scanner they can prolly get a code out of the module that controls it.

Usually a bad pressure switch will keep one running all the time. I wouldn't waste time or money changing lines, ect.
Looking at the diagram for your system, the AC module controls the ground for the relay that turns the compressor on. If that relay is stuck on then the compressor will run all the time. See if you have another relay like it (horn, headlights, ect) and swap it with the AC relay to see if the relay is bad.

Maybe this helps:


Dodge Part # 5073617AA



The A/C pressure transducer (1) is a switch that is installed on a fitting located on the A/C discharge line. An internally threaded fitting on the A/C pressure transducer connects it to the externally threaded Schrader-type fitting on the A/C discharge line. A rubber O-ring seals the connection between the A/C pressure transducer and the discharge line fitting. The A/C pressure transducer is connected to the vehicle electrical system by a molded plastic connector with three terminals.

The A/C pressure transducer monitors the pressures in the high side of the refrigerant system through its connection to a fitting on the A/C discharge line. The A/C pressure transducer will change its internal resistance in response to the pressures it monitors. A Schrader-type valve in the A/C discharge line fitting permits the A/C pressure transducer to be removed or installed without disturbing the refrigerant in the A/C system.

The A/C pressure transducer will change its internal resistance in response to the pressures it monitors. The powertrain control module (PCM) or the engine control module (ECM) (depending on engine application) provides a five volt reference signal and a sensor ground to the A/C pressure transducer, then monitors the output voltage of the transducer on a sensor return circuit to determine refrigerant pressure. The PCM/ECM is programmed to respond to this and other sensor inputs by controlling the operation of the A/C compressor clutch and the radiator cooling fan to help optimize A/C system performance and to protect the system components from damage. The PCM will disengage the A/C compressor clutch when high side pressure rises above 3172 kPa (460 psi) and re-engage the clutch when high side pressure drops below 1999 kPa (290 psi) . The A/C pressure transducer will also disengage the A/C compressor clutch if the high side pressure drops below 193 kPa (28 psi) and will re-engage the clutch when the high side pressure rises above 234 kPa (34 psi) . If the refrigerant pressure rises above 1655 kPa (240 psi) , the PCM will actuate the cooling fan. The A/C pressure transducer signal to the PCM/ECM will also prevent the A/C compressor clutch from engaging when ambient temperatures are below about 10°C (50°F) due to the pressure/temperature relationship of the refrigerant.The A/C pressure transducer input to the PCM/ECM will also prevent the A/C compressor clutch from engaging when ambient temperatures are below about 10°C (50°F) due to the pressure/temperature relationship of the refrigerant.

The A/C pressure transducer is diagnosed using a DRBIII(R) scan tool.

The A/C pressure transducer cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

Man you guys are awesome! I'll check the pressure switch and let yall know how it works

I work at a Honda dealer now but started at chrysler for a few years. They have a lot of weird control module and wiring problems. I had a quad cab dully one time that hada weird ass ad problem one time and it ended up being that style pressure switch. The way it is designed you can pull it off and install a new one without evacuating system. With it being the 5 volt reference type you really gotta know what your doin to check it without the drb (Chrysler scanner)

I dont want to hijack this but I have a problem I want your input on if you dont mind. I just got my 03 LQ4 into my 06 TJ and have had it running a couple weeks Im finishing the odds and ends now and trying to get the AC back working this has turned into a challenge I had Novak to rework my factory engine harness and leave me a AC switch wire and a wire for the pressure sensors and compressor.
The instructions they sent says to supply a 12V+ from the original jeep AC dash switch (06 TJ) to the GM ECM and use the other wire supplied in the harness to the pressure switches wired in a series in and out the first switch to the second switch in and out to the AC compressor they installed a 20 amp relay in the harness for this also the problem is that there is no 12V+ on the jeep AC switch when it is turned on like they are wanting me to use. I need to go thru the GM ECM to activate my electric fan (single fan) when the AC is turned on my GM ECM also has the idle up control turned on for this function also
Could it be as simple as using just a push button AC switch to supply the 12V+ to the GM ECM like they are wanting ? and then just let my factory jeep AC dash controls operate the functions such as vent, floor, defrost, temp, ect let me know if anyone has any ideas or has done this swap into a TJ and are using your factory controls to work the GM compressor

ALLJ said:

The instructions they sent says to supply a 12V+ from the original jeep AC dash switch (06 TJ) to the GM ECM

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Find the AC compressor clutch relay in the Jeep power distribution center, use the +12 output from it and go to the GM ECM. Assuming you still have the Jeep PDC in place.

grcthird said:

Find the AC compressor clutch relay in the Jeep power distribution center, use the +12 output from it and go to the GM ECM. Assuming you still have the Jeep PDC in place.

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I do still have it I will try that thanks for the info and again I didnt mean to hijack colts thread but after reading the responce yall gave him I figured you may be able to help me

Looks like the electronic fan clutch is the culprit. I got it blowing cold using water to cool the condensor. The problem now is getting the threaded hub on the fan clutch to break loose. Aaaahhhhhh! Im gonna set this joker aflame! After major surgery i have the ehole fan mount and bearing with fan still attached in the vise. Gonna get a 36mm open end tomorrow and try again. It never ends. Update and fire pic to follow.... fan clutch...

They just can't build anything to last anymore.

grcthird said:

They just can't build anything to last anymore.

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Aftermarket clutch worked for 15 minutes and stopped spinning. What a piece! Putting a dodge clutch in next. It never ends. AC is fixed though, we can't use it at idle. I had 2 dodge techs tell me the aftermarket stuff doesnt work at all!

use an airchisel and bump it loose with the belt still on. Then you can spin i off with your hand.

Move to Alaska...