I attempted to add refrigerant to my 2006 diesel 2500 and what appears as the low side AC service port is too large for the standard size AC service port coupler that has been used on several other vehicle makes for the low side service port. The port I am referencing on my engine sets on the left front and is the larger line service port. I called Dodge and they said all their service ports on low side are standard size. I have either been trying to couple to the wrong port (which there are only two for AC one large and one small) or something goofy exists on my truck. Does anyone know for sure exactly where the low side AC service port is located on a 2006 Ram 5.9 diesel 2500?

 

The large one is the high side. Have you tried the other port?

 

Thanks. My AC pressure test kit and all blogs I have read say the low side AC service port is always the larger of the two lines. I tried the small line with a test pressure of 150 lbs. and of course that is not where you would add refrigerant.

 

Alldata says the high side port is on the AC discharge line, the low side is either on top of the accumulator or on the AC suction line near the accumulator.

The low side port is smaller, but it's on the larger diameter line.

 

06 is on the accumulator.

 

I have the same problem with my 2002 3500. I have heard there is a special adaptor needed . I have tried universal kits and 2 others and none fit the nipple. My grand daughter delivers parts for NAPA and had to get my son one of those adaptors so the kit you buy in the auto stores will fit.

 

They're all standard sized ports, I'm not sure why you would need an adapter. If it works on any r134a system, it will work on your truck. If the test port is too big, use the other one.

 

I have tried them on both and they will not fit over either one.

 

Do you have R12 connectors on your gauges?