2004 Dodge Ram 2500 AC high side at 430 PSI at idle

[Fluxunstopable]

Earlier this year I replaced every line, the compressor, condesor and the filter drier. I have not replaced the evaporator because of not taking the dash apart yet. I have a 10in electric fan mounted directly on the condensor and replaced the electronic fan clutch with a mechanical one. Before I did all of this I had the same issue. When the truck is moving and driving the AC is cold and heas pressure drops to 250ish on a 80-85 degree day. What would be the case of this? Dirty evaporator? Bad HPCO switch?

[Cusser]

State whether the pressure was measured at about 2000 rpm, that's important.

When you monkeyed with the original cooling fan system, did you retain the fan shroud?

[tbirdtbird]

1. why were all those parts replaced? did the compressor grenade?
2. as Cusser states, you have a condensing issue. This is not the HPCO. Could also be overcharged, or too much oil
3. 10" doesn't sound like much.
4. Need pix of any fan setup on the truck at this time, before or after the radiator.
5. need hi and lo pressures at 1500-1800 RPM along with vent temp (using thermometer), and ambient, with AC on max cool max evap fan, doors open (full load test)

[mswankca]

Earlier this year I replaced every line, the compressor, condesor and the filter drier. I have not replaced the evaporator because of not taking the dash apart yet. I have a 10in electric fan mounted directly on the condensor and replaced the electronic fan clutch with a mechanical one. Before I did all of this I had the same issue. When the truck is moving and driving the AC is cold and heas pressure drops to 250ish on a 80-85 degree day. What would be the case of this? Dirty evaporator? Bad HPCO switch?

What fixed this truck? I have same truck in with same symptoms after service.

[tbirdtbird]

Thread is almost one year old. You may not get a reply, as often happens here.
Start your own thread with a detailed list of your problems and what your setup is, incl make/model/year