Car sits for a week, get in and no A/C?

Zeke · 01:35 PM

Suppose I hit something and damaged a condensor and the refrigerant leaked out?

Here's what seems to me to be weird. I moved the temps from low to high, felt the heat coming in, moved the temp back to low and felt the engine pulling the A/C pump. Why would there be any pressure left in the system to cause drag? The computer changed the idle speed to keep it at the same 800 or so RPM.

What else to look for? Lots of air coming out of the vents. All vent systems working and the fan speed regulates according to how close I set the temp to the ambient.

Just no (none, not a hint) cold air. Last time driven it was perfect.

One last thing, I have a Durametric. Will that show me a code for no refrigerant?

air conditioning, air, conditioning, air-conditioning

TIA.

Zeke · 06-19-2012, 01:34 PM

How can I add tags to my post? I should have said "air conditioning" instead of A/C. A/C doesn't search well.

nosnow4pc · 06-19-2012, 01:36 PM

supposely on early cars there is a function on the A/C head that will tell you pressure and various other climate control system variants.

i had a simular situation and bought a kit from Autozone for $40. I filled it with refrigerant and now have a handy gauge to check pressure. For what it is worth it took two cans to fill it up.

Zeke · 06-19-2012, 01:53 PM

Thanks. I have some a/c experience. No vacuum pump though. I won't waste any refrigerant until I find the cause.
Haven't run the codes yet, so I don't know if there is a fuse. I thought about a belt breaking, but I'm curious as to the RPM change and computer adjustment to idle speed.

Wish my old truck had that feature, it just bogs down and shakes at idle with a/c on.

nosnow4pc · 06-19-2012, 03:09 PM

I was told that there is a wire on the compressor that sometimes comes off as it is low to the ground. If it was a sudden stop and it doesn't cycle I suggest looking under the car to see if you are lucky.

Zeke · 06-19-2012, 03:24 PM

Thanks. I'll do a survey for physical evidence.

Zeke · 06-21-2012, 06:55 PM

Anyone else?

tomk · 06-22-2012, 08:53 AM

my money is on a low charge, the only way to really tell is to put some gauges on it, the idle function you describe sounds normal

Cajundaddy · Cajundaddy's Garage

Mine failed gradually and was a simple refrigerant leak discovered with dye. Another possible cause is a stuck/failed mix flap preventing air from flowing through the evaporator.

Zeke · 06-22-2012, 03:37 PM

Failing gradually is what I'd expect. I seem to remember that running a/c with little or no refrigerant can damage the system.

bell · bell's Garage

there is a low pressure switch (right near the ports and the cabin filter) which will keep the compressor from turning on when the pressure is to low..
the boxer should take right around 2lbs of r134, the low pressure switch will trip when it gets around .5-1lb......

gauges are the only way to know what the pressures are doing, the only way to know the volume of refrigerant in the system is to evacuate it into a machine. most places will do this fairly cheaply, I would do it for you if you were local....

bell · bell's Garage

oh.....and the low pressure switch will keep the system from destroying itself so it s doing it's job...

Zeke · 06-23-2012, 09:23 AM

Quote:

Originally Posted by bell

oh.....and the low pressure switch will keep the system from destroying itself so it s doing it's job...

Thank you. I will have time to investigate tomorrow. I don't have R134 gauges, just the old stuff which I won't need much longer. When it comes to R134, I will leave that to a shop.

Zeke · 07-25-2012, 07:48 AM

Testing by a shop turned up the evaporator. The bill is 2K.

Ouch. I don't think there's anything you can do to prevent this. **** happens.

Had the car since 2002 and it's got 58K on it. Looks like I'm in that zone where it's time to dump it.