Needed- Late model Dodge Truck AC help

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Hemihead2

Hemihead2

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Hello- Any Mopar techs out there that are willing to dive into my 2005 Dodge Ram 2500 Air Conditioning trouble?? Obviously it will be online and not in person, but I just can’t figure out what the problem is! If you are able to help please PM me and I’ll fill you in. Thanks All!
 
Yep, spill it.

I'm dealing with a minor issue with my 2000 Dakota A/C.
 
Ok- I posted this over at Moparts as well.

Hello- if someone would be interested in helping me solve an AC problem I’m experiencing in my 2005 Ram 2500, I’d appreciate it. I can fill you in on more of the details via PM. Thanks in advance.

1. System was vacuumed and held -30 for 10 minutes.

2. Filled to OEM capacity with 134a

3. Reman compressor- clutch engages and condenser fan turns on when switched to AC. Recirc door works, blend doors responds to input- dual zone controls- on heat zones get hot on cold- zone become like warm.

4. Laser temp of evap core- 78* with AC on, laser dash temp of vents- 78* w/ AC on

5. Accumulator freezes up when charging- high side line after the expansion valve also freezes up but no coldness enters or exits the evap core. BUT both lines to the core have been disconnected and compressed air blows through freely with no apparent restriction.

6. AC line to and from the compressor are NOT hot when AC compressor clutch is running.

7. Hooked gauges to high and low side and ran compressor. Both read 110 with compressor off- but BOTH increased to 125-130 with compressor cycling on.

Bottom line- system is charged and responds when AC is called for but evap core is not getting cold and consequently there is no cooling in the cab.

Any ideas???
 
The low side does not try to pump low? When compressor runs does it short cycle? If both sides stay high and you are sure compressor is actually turning, I'd say bad valves in the compressor

What is the history? Did someone over charge it or charge liquid "too fast" into the low side and take out the valves?

AND ARE YOU SURE YOU HAD BOTH GAUGE VALVES SHUT when taking readings?
 
67Dart273 said:
The low side does not try to pump low? When compressor runs does it short cycle? If both sides stay high and you are sure compressor is actually turning, I'd say bad valves in the compressor

What is the history? Did someone over charge it or charge liquid "too fast" into the low side and take out the valves?

AND ARE YOU SURE YOU HAD BOTH GAUGE VALVES SHUT when taking readings?
Click to expand...


Compressor does not short cycle and stays on the whole time….

I retested with the valves closed and low side pegged at -30!
Shut it off and low side slowly rose to 75 while High settled at about 95.

The high side line from orifice back to evaporator coil was frozen..until I turned the compressor off.

Sound like a blocked Orifice?
 
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Yeh, blocked and or moisture in system. so the bogus pressures were with guage valves open? You essentially had the compressor high and low sides open to each other.

It's not a TXV is it? They can go bad and "not operate" IE not pass refrigerant.
Did the system lay around "open" and absorb moisture? One way to combat that is to get the vehicle damn good and warm, engine "fully" warm. Run the cab heater to get the evap warmed up. "Flash some refrigerant through the system. Do that by leaving the low side open (hose off the gauges) and dump some refrigerant through the high side, it will go clear through and come out the low, hopefully flushing out most moisture. Compressor does not need to run for that. Then re-evaculate, with engine still "hot." That will help drive out moisture

Also running as you describe with gauge valves closed and that low evap, compressor should now short cycle on pressure switch
 
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I vacuumed the system for 15-20 minutes hoping to get all the moisture out. It held -30 for 10 min afterwards. The system was only open when I changed out the compressor. That’s when the trouble started. I also changed out the drier more recently thinking it may have been part of the issue.
 
Just looked it up- my truck only has an orifice no TXV.
 
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