Air Conditioning clutch not engaging?

[baron1701]

Yesterday my A/C was a little warmer than normal. I was messing around with a brake repair so I decided to put a can of refrigerant that I had kicking around. The car responded well with some very cold air. While I was filling, I noticed that I didn't hear the a/c clutch engage. I checked with a pressure gauge and all was well. Later that night I noticed that the a/c had just quit.

This morning the a/c worked fine. I also have a dull thumping at idle that I cant explain. Could this all be indication of a compressor failure? I have no lights on and a 1995 that cost a hundred to have scanned. If this is an indication of failure, should I buy a 'shorty' belt and replace the compressor before it siezes and sends junk thru the entire system? There is no other sign of failure. Tonight i am going to see if i can turn the clutch. I think it should spin freely.

[kdog_x]

Originally Posted by baron1701

Yesterday my A/C was a little warmer than normal. I was messing around with a brake repair so I decided to put a can of refrigerant that I had kicking around. The car responded well with some very cold air. While I was filling, I noticed that I didn't hear the a/c clutch engage. I checked with a pressure gauge and all was well. Later that night I noticed that the a/c had just quit.

This morning the a/c worked fine. I also have a dull thumping at idle that I cant explain. Could this all be indication of a compressor failure? I have no lights on and a 1995 that cost a hundred to have scanned. If this is an indication of failure, should I buy a 'shorty' belt and replace the compressor before it siezes and sends junk thru the entire system? There is no other sign of failure. Tonight i am going to see if i can turn the clutch. I think it should spin freely.

The A/C clutch won't engage if there isn't enough pressure in the system (i.e. a leak) I noticed when I was filling mine up that the clutch wouldnt engage... I ended up putting 75 PSI of pressure in and it still didnt wouldnt budge. I shut the car off to check it out... started it back up... and then it decided to kick in. This might be why it got going again in the morning.

If you want to find out if the compressor is causing your thumping noise, start the car and run the A/C on MAX. Then push the "A/C" button to deactivate the compressor and see if the sound goes away. If it does you might try turning it by hand like you mentioned. If it seems kinda rough, stop using the A/C immediately, it's a big PITA to get all the metal out of the system if you dont, and you might end up needing to buy a condenser as well.

PS My 95' didnt have any engine lights on when the compressor completely seized up, so you probably aren't going to see one either.

[baron1701]

I tried to add some refrigerant yesterday and the can nearly shot off. When I got home I put my a/c pressure gauge (no psi rating, just colors) on it and the pressure was way over in the red, all the way almost. I relieved a ton of pressure and brought it down into the green. The a/c clutch was cycling but wasn't getting any colder. When the a/c would cycle it made a funny noise, like air releasing. My compressor starting making noise and actually stalled the car out. At this point I shut the a/c off and told my wife not to use it. We drove the car a bit more last night and had no noises or smells.

This morning I tried the A/C for the heck of it and she worked perfect. I don't know what to do now. I think I may have damaged either the compressor or clogged the condensor by having that much pressure. If it still works tonight, I think I will flush the system w/ a kit I saw and refill. I wonder why the system didn't release the pressure.

Perhaps the noise I was hearing was the compressor's pressure relief valve opening everytime it tried to add pressure to an allready overtaxed system. Why then would it work the next day as though nothing happened?

[kdog_x]

When filling the system, that noise is normal, the gauge should rise to about 45-60 PSI (probably the red zone on your gauge) then there should be a hiss and the gauge should drop to 5-25 PSI as it takes in the charge. Then pressure will build back up and this cycle should repeat. I dont know for sure, but if the compressor stalled the car out... I'd say maybe the clutch is starting to go out. With the pressure building up like that, you may have a clogged orfice tube. you can try replacing it ($5) and recharging, but if it keeps clogging your compressor is probably releasing debris into the lines and will need to be replaced. From just about every review I've seen of the car... the life of the A/C compressor usually comes to a halt between 100-150k miles.

Just a note... If you open the system to clean the lines you should replace the accumulator. It absorbs the moisture from the system and should be replaced any time you open the lines. Also, before recharging, you need to pull a vacuum on the system to boil out any moisture that could be in the lines. I did it for two hours on mine just to insure the coldest A/C possible. The service manual says to do it 30 minutes minimum though.

[autmseas]

I have cold air coming out of passengers vents and not the drivers side, on ocassion becoming more than ever. I took it in to a lube shop running a special on checks. He informed me that I was low on freeon. And everything else seemed to be fine and I had to correct him and inform him of the problem I was having. About a half hour later he gave me a estimate for a new compressor. I drove home and had no ac at all!! The coolant line is icy cold but no cold air blowing in cab,,any suggestions? Before I spend $$$$$. Thanks. 95 auroa

[baron1701]

Alright,
I have regulated the pressure where i think it should be and still nothing but warm air. This all happened after I over charged the system. Could I have clogged the orifice tube and that is now blocking the system up?

If the compressor was the problem would the pressure still seem to cycle properly with the compressor clutch?

[kdog_x]

Originally Posted by baron1701

Alright,
I have regulated the pressure where i think it should be and still nothing but warm air. This all happened after I over charged the system. Could I have clogged the orifice tube and that is now blocking the system up?

If the compressor was the problem would the pressure still seem to cycle properly with the compressor clutch?

Unless the compressor is failing, or debris got into the lines somehow, your orfice tube shouldnt be clogged.

If it's cycling, lets assume for the moment that the compressor is fine.

Does the system cycle while it's just sitting there at idle?
What pressure did you regulate it to? Is it at a steady pressure or is it cycling?

[kdog_x]

Originally Posted by autmseas

I have cold air coming out of passengers vents and not the drivers side, on ocassion becoming more than ever. I took it in to a lube shop running a special on checks. He informed me that I was low on freeon. And everything else seemed to be fine and I had to correct him and inform him of the problem I was having. About a half hour later he gave me a estimate for a new compressor. I drove home and had no ac at all!! The coolant line is icy cold but no cold air blowing in cab,,any suggestions? Before I spend $$$$$. Thanks. 95 auroa

Cold air on the passenger side IS a sign of low freon. A simple charge will probably get it working again TEMPORARILY. If it's low, then there must be a leak somewhere, freon does not get consumed over time. The tech most likely thinks it's an internal compressor leak. Did he tell you how he came to that conclusion?

[baron1701]

Kdog,
Thank you for all the advice.

Yes, the compressor is cycling during idle and while running. The pressure climbs and then the compressor engages and the pressure drops. I have it so the gauge goes into the high green and the goes down below 20. I should have written the numbers down, but i'm confident that the pressure is ok now. My question is, if the compressor is cycling, then what? By overcharging the system, what componet could I have overtaxed. I am thinking of doing the orifice tube and a system flush. That way if the condensor is clogged I might be able to clean it out. I wouldn't mind doing the condensor if I was sure it was the problem.

If the overcharge triggered a code to the body contol module that a pressure problem existed, would that code reset by itself or would I have to pull the battery cable off for an hour or so? Unfortunatley I have an OBD1 so reading codes is an expensive problem and I dont have an engine light.

[autmseas]

yes, This is his what he put on my estimate. If it may help any one else too.Duct tempetpreture is with in .30 degrees from each other. Inspection of sysem found .50 lbs in system with exessive moisture at front of compressor, charged system for testing and activated compressor, high side off the chart, and vented from pressure release. Compressor has failed and is leaking. will require flushing of a/c line,orrfice tube replacement and accumulator replacment. My husband just does not understand why the lines from the compressor are icy cold if the darn thing is not working

[JWDurden]

As A/C clutch wears the face of the magnet is worn away, increasing air gap the magnetic field must bridge, taping clutch while it should be engaged may cause it to pull in, also reving engine can do the trick, but it may not come back in each time it cycles. Considering difficulty of replacing it, a new one is best bet.

[aarcuda]

never work on an ac system without hi and lo pressure guages. if theres a clog, that compressor can reach 450psi or more and blow somehting up.

you might have been hitting the high side limit and had the hi pressure switch cut the compressor off. the question is- what was the high side pressure? if you dont know, you shouldnt be messing with the ac.

[zimaad]

You say it is "cycling". That doesn't necessarily mean it's cycling correctly. It shouldn't cycle too fast and you need to know the high and low pressures to really know what's going on. I'm willing to bet your compressor is about to go. If it hasn't been replaced, it's probably time it was. It's probably already unloaded some crap into the orifice tube which is affecting pressures too. If pressures are going up and down quickly, the compressor is sensing a quick buildup in pressure....likely a blockage in the orifice tube. Go to and A/C shop and get it looked at. It's doable as a DIY, but changing a compressor is a pain in the butt. You really do have to do a lot of steps and have the right tools to do it. You need manifold guages(not a color coded low side guage), flush...flush...more flush, A/C oil, a vacuum pump, etc. It definately will cost some money to get it fixed. One other thing..if the orifice tube has any crud in it at all, replace the condensor too because it probably has crud in the small size HX fins.