Dodge Grand Caravan AC - 2001

[Diametric]

Hello!
I'm working on a 2001 Dodge Grand Caravan I have owned for about a week now. I am not getting cold air at the vents.
When I first checked the system it was low on refrigerant but still had some pressure and about 15oz of refrigerant so I assume it wasn't exposed to atmosphere AFAIK.

(I recovered the freon, vacuumed the system, then waited several hours. No leak detected. Filled with Nitrogen via low side to 150psi and left overnight. No leak detected.)

After vacuuming the system down again I added 32oz of refrigerant per the factory service manual.
A few observations.....

When I FIRST turn the AC on, the suction side aluminum pipe gets VERY cold, but within 1 minute warms back up and is no longer cold. The high pressure line gets very hot.
Pressures are good when running - 35psi and 290psi (good according to the Factory Service Manual) at the ambient outside temp of 96F. When not running, pressures are right at outside ambient.

Would you say the fact that it gets ice cold for a minute suggests at least the compressor is working or do bad compressors sometimes do this (compress the gas for a minute...then not)

Unless an evap core is leaking, I don't usually have any problem with them. Condensers even in my 35+ year old vehicles seem to keep working just fine as long as they're not damaged or punctured. Exterior fins get damaged and external crud seems to reduce their capacity but I haven't ever had a total failure of a condenser.

Just overall...is this likely to be an expansion valve or accumulator issue (or not enough info to tell)?
I looked at ACKits.com and they have competitive pricing so I'm probably going to buy what I need that I don't already have there.

[JohnHere]

Contrary to the Factory Service Manual, elevated pressure on the high side usually indicates a condensing issue. At a 96°F ambient temperature, the high side should be ~225 PSI with decent condensing.

Do you happen to know whether the condenser and fan(s) have ever been replaced?

[Diametric]

Contrary to the Factory Service Manual, elevated pressure on the high side usually indicates a condensing issue. At a 96°F ambient temperature, the high side should be ~225 PSI with decent condensing.

Do you happen to know whether the condenser and fan(s) have ever been replaced?

Hello JohnHere!

As far as I can tell neither has been replaced. But they both look good and the fans seem to operate properly.
I personally find it stunning that the FSM would publish erroneous information on the vehicles they built.
According to their information, 225psi would correlate to an ambient of closer to 80F ?
The FSM figures are also for R134a which is what I am using in it.
Would you mind telling me how you came up with your ~225 psi figure?

FSM AC Pressures Chart.jpg (57.26 KiB) Viewed 60 times

[Diametric]

I've only had this vehicle just over a week now and yesterday checked for the first time.....

Yep...REAR AC. Found lots of Oil at the expansion valve so this changes everything. Now I'm going to remove the rear evaporator to check for leaks and most likely replace the rear expansion valve and change the seals.

Nice find. Rear AC is good.