Air Conditioner Problem

Yep. Probably no charge...

Ask here for more info:

Low refrigerant will shut it down. This is to protect the compressor until the cause is fixed. "ancienité" Good word. Thanks.

Year, model, compressor type?

Most Mopars since the 80s will shut off for *either* high head pressure or low suction pressure. Some of the 80s "block" style expansion valves were a little prone to plugging, and would result in the compressor running for a second or two until the head pressure went too high, then the safety switch would cut them off. But in that case, the discharge line will get hot quickly. Low suction pressure is MUCH more common, though, and sounds like your situation. Without sticking a set of guages on the system, its something of a SWAG ut I'd guess low charge since that's more common.

It is a 1997, Custom built on a B2500 chassis, 318 cid FI engine. Compressor seems to be the TRF-105.

Im going to take good look to see if I can spot a leak, then put the gauges on it.

I am also having some coolant loss, which I dont believe had anything to do with the AC problem. The hurricane drove a pecan limb through the front grill, but it didnt seem to come close to either radiator or condensor. More later.

Yes, a possible cause. Sometimes a pressure is enough in the system to start the compressor, but once its runing, it expects a higher pressure, and not meeting it, it shuts off.

Get a buddy( Qualifed) with a manafold to verify this. Many auto places won't check without paying for a full AC check upfront.

hth,

tom

I will do that. I dont have gauges or equipment anymore, and have more conscience than just to give it a dose of 134a. The coolant loss, mentioned previously, was only about a cupful, and I believe it was only incidental. I dont drive this unit much anymore.

Thanks to all.

Thanks to all who calmed my unease on this issue. I hated the idea of $600 for a compressor, system washout, recharge, etc...

And as with many things, when the diagnosis is made, the fear is worse than the disease.

I took off the cap from the low pressure side to attach the manifold, and immediately saw bubbles from the valve. Just a leaker, which I hope I can resolve by tightening, and topping off the refrigerant.

Was the schrader valve actually loose? It may not be seating. If refrigerant is very low anyway, now's the time to change both of the scrader valves. Get A/C specific valves from an auto parts store; they look just like tire valve cores but they are designed for the task. (Making the broad assumption that your Van employs the very common style schraders that are available at virtually any parts store -- also making the assumption that you found the *only* leak without proper leak diagnosis)

Toyota MDT in MO

Toyota MDT in MO

The valve was a little loose. I tightened it slightly and the bubbling stopped. Hope this is all that was needed.

I charged 12 ounces of 134a, and the compressor is now staying on and cooling. The suction side pressure is still a bit on the low side, but I will not charge further until I see how it is going to hold up.

Hi,

I wonder whether there was some cooling felt from the system even with so little compressor circulation ?

I think I had the same problem, and also had a low coolant pressure diagnosed. But the system cooled the air just enough to accept the condition for a while.

Peter

schreef in bericht news:B6Ncf.18400$ snipped-for-privacy@newssvr29.news.prodigy.net...

Before I added the coolant, there was no cooling at all. One could touch the high pressure line from the compressor to the condensor under the hood of the car and feel no heat....that section is usually uncomfortably hot to the touch.

The Schroeder charge valve was found to be leaking slightly, and over time all the refrigerant (well, not all, but most of it) leaked out. Slightly tightening the valve core and recharging the refrigerant seems to have solved the issue.

Quite likely. Just get to it and get a full charge back in it before it gets down to ambient pressure- R-134a systems are REAL susceptible to moisture contamination. Moreso than R-12 was.