Ok guys, had my favorite little van in for service recently.

i have owned it for a few years now. The AC never blow cold air and I just did not worry about. My local shop does AC and replaced my blower fan that I just did not wish to try and tackle so I asked them to check it out.

When all was said and done they checked it, charged it and said it worked. Well great.

Well a week has gone by now. Yes it did/does blow cold sort of. Seem's less cold now than a week ago. But the bigger issue is when it is on about every seven seconds something clicks on, runs (rattles) for about 3 seconds and shuts off. This cycle repeats itself all the time the AC is on. I figured it is the compressor. But do not think it should run like that?
What can you tell me and what should I do?

It is a 2000 safari rwd. Thanks guys.

This message has been edited. Last edited by: old rugged cross,

My guess is a freon leak, the system has a pressure switch that when it see's low pressure it turns off compressor. Unless you own or you can rent a vacuum pump to recharge after leak is found or back to shop.

On my daughter's old F150, I used the "freon" from Autozone that hooks up to the low pressure port. I followed the directions, and it charged to a good pressure level. The leak prevention chemistry has taken care of the seal leaks, and the truck has had cold air for two months. A great $45 spent.

Yep, try a can of seal conditioner first(stop leak as I call it)

If that don't get it, either the compressor seals are leaking or the O rings in the fittings are bad.

The compressor is cycling on and off excessively because of low charge, which, since it has been charged multiple times, means there is a leak somewhere. If dye has not been put in it, do so, then go over everything with a UV light. One common leak is the compressor itself, but the tight quarters of a van makes it difficult to see. Also go over the hoses and the condenser. Evaporator core leaks aren't common on GM vehicles, but it can still happen. Find where the water drains and look for a residual dye trail. If this is a passenger van with rear HVAC, you have additional plumbing underneath and a second evaporator core to look at.

I'd look at the Schrader valves in the connectors where the A/C gauges or machine is hooked to the system. Many times these will not reseal after a service, especially if they are original or have been in there for quite some time.

First mix some dish soap and water in a squirt bottle. remove the two caps, run the A/C and squirt into the connectors. You should not have any bubbles. If you see bubbles, the system should be drawn down and the valves replaced before recharging. If no bubbles present, you can use the soapy water solution to spray down other A/C hose connections.

One place on the compressor that likes to leak is the front seal. Many times it is just too damned hard to get the soapy solution to reach in there for a definitive diagnosis and a freon detector has to be used. But spray the front of the compressor with the engine OFF.

I will never use a sealer in the A/C system, that shit can and will gum up the works.

If the orifice tube is blocked, you will more that likely see icing where the blockage is. The orifice tube on GM's is usually near the accumulator near the box that houses the evaporator.

Compressor cycling on low pressure switch due to leak and/or restriction.

Leak could be anything from an o-ring, seal, bad hose or condenser coil.

Restriction is normally at the metering device or orifice screen/filter (if so equiped).

Thanks guys. Very helpful. This is not a fix I am up for.

Yes guys it is cycling like you say. That is the answer that makes sense to me. Appreciate all the thoughts and advice guys. It will go back soon.

E, it does have rear AC. At Least there is a separate control for it. So I assume so.

 
Don't AC/auto repair shops have a die they can put into the coolant? The one I've seen was green. It quickly revealed where the leak was.
 

Yes and they did according to talking with them this am. Going back in on Thurs. I have a suspicion that it may be the second evap.core as Egregore said. We'll see. But that on/off incesently is problematic for sure. Is that just because it is low on juice or is something else a matter?

Again thanks guys.

I bought a halon detector from Amazon for around $45. Although it looks like Chinese junk, it worked like a champ to find my AC leak. Way better than a dye test.

So after another shop visit it turns out it needs a new compressor.

$415 installed was the quote. I am not surprised. Van is almost 20 years old. Less than I thought it might be. I am thinking it over. It would be nice if it worked. Lots of things pulling at the minimal pool of available funds for things right now though.

Would you fix it?

The van is in decent shape with low miles. About 120k.

To save money you could buy the compressor yourself then have a shop install and charge. You can check summitt racing .com their parts and prices are better than most. And check the price for installing your new compressor. Get second opinion before you buy one.

Compressor ordered. On the schedule for install late next week. I sure hope this is the long term fix for my van and its AC. Fingers crossed. It would be real nice if it work for at least the next five years so I can enjoy the summers in comfort.

This message has been edited. Last edited by: old rugged cross,

It should also be possible to rent/borrow a vacuum pump from a parts house. Change it out yourself if you can. Draw a vacuum on it for several hours to eliminate moisture in the system. Charge it and enjoy the fruits of your labor.

saga continues. The low pressure switch needs replaced too.
I indicated that it was not functioning properly before the last appointment. Doh!

We do not have many choices and I do have some history with this shop but still a bit aggravating. Just have to deal with it in small town USA.

They ordered a OEM switch so it will be sometime next week.

I guess I am in to far to look back now. Only 100+ today.

quote:

Originally posted by Shifferbrains:

I will never use a sealer in the A/C system, that shit can and will gum up the works.

Yep, using any leak sealant in an auto a/c system will only cause problems and will end up costing more in the long run. You may get a cheap, temporary fix but it will cost you down the line.

Ok guys, pickup last nite. Put back together with new compressor and switch.

Blows cold, sweet!

Lets hope that is the end of it and it keeps on going for several years now.

So a couple of questions. Is there anything one should do in the months when not using AC to ensure everything keeps on working when itis needed?

Also on my rig there is an AC setting and a Max AC setting. Why is this and what is the differnce. Does the Max stress the system more than the std. AC setting. I am guessing it produces a cooler temp. Have not tried it yet. Should you use the std setting unless it is really hot?

Thanks guys. I appreciate all the comments.

quote:

So a couple of questions. Is there anything one should do in the months when not using AC to ensure everything keeps on working when itis needed?

I have AC in the cab on my tractor.

New in 2015.

Spring of 2016 - No AC. Leaking oring at compressor, replaced under warranty, recharged all good.

Spring of 2017 - No AC. Leaking oring at evaporator in roof of cab. Replaced under warranty (service writer actually fudged the paperwork to sneak it in, it was about 2 weeks out of warranty) - all good.

Asked if this was going to be a continuing problem and what, if anything, I could do about it. Their AC guy said it usually isn't, but could go either way, and best thing I could do is fire up the AC once a month or so during the off season to keep the orings lubed.

Did so Winter of 17/18, no problems since. Could be a thing, could be coincidence, I dunno.

One most cars the AC runs in the winter too, if you use "defrost" setting. The AC runs, even if using the heat to help with dehumidifying the air to help with condensation... So it may not sit as much unused as you think.

Max AC usually does a couple things. Boosts the fan speed, and closes the fresh air intake. With the fresh air intake closed the AC only recirculates the inside air... So it can cool more or faster on a hot day by not having to cool off the constant input much hotter outside air.