air conditioning problem
Thread Starter
Heel & Toe
Joined: Mar 2004
Posts: 23
Likes: 0
From: Columbia SC
air conditioning problem
I think I have a major problem.
The air conditioning compressor will not engage, only when I jump it will engage. The 10amp fuse for the AC is not blown but there is no power at the fuse. I put a test light on it and nothing. Does this mean that the switch in the dash is bad? I jumped the fuse and the compressor still did not come on. The wire diagram looks like it goes back to the dash switch.
When the compressor engages it is reading very high on the high side (over 280-300). How can I tell if the system is blocked? The only time it was opened was to replace the condenser and radiator. The high pressure switch on the compressor would not be the cause the high pressure would it?
Man this thing is driving me crazy.
The air conditioning compressor will not engage, only when I jump it will engage. The 10amp fuse for the AC is not blown but there is no power at the fuse. I put a test light on it and nothing. Does this mean that the switch in the dash is bad? I jumped the fuse and the compressor still did not come on. The wire diagram looks like it goes back to the dash switch.
When the compressor engages it is reading very high on the high side (over 280-300). How can I tell if the system is blocked? The only time it was opened was to replace the condenser and radiator. The high pressure switch on the compressor would not be the cause the high pressure would it?
Man this thing is driving me crazy.
Last edited by rddaves54; Aug 13, 2007 at 01:02 PM. Reason: spelling
Instructor
Joined: Aug 2007
Posts: 212
Likes: 0
From: www.C4guru.com Everywhere!
It might be the A.C. relay switch. Also, I heard that if its to low on freon, that the system wont start. Just what I heard from a local shop but I wouldn't trust them as far as I could throw em.
Last edited by Corn Flakes; Aug 13, 2007 at 01:02 PM.
Thread Starter
Heel & Toe
Joined: Mar 2004
Posts: 23
Likes: 0
From: Columbia SC
I pulled the fuse to at the accessory fuse and the compressor is engaging but it does not seem to want to stay on and pull in a can of Freon. Could the system have a block or the orfice tube be clocked?
I put the gages on it and it seems to be 150 on the high side and on the low side I was not sure. I put a retrofit on it the other days and it can with three cans of 12 oz. I put in two or most of two that would not even be close to filling an empty system, right?
It is not cooling but the compressure is coming on so at least the electrical system is working right?
Now I just have to see why it will not take Freon.
Any suggestions?
I put the gages on it and it seems to be 150 on the high side and on the low side I was not sure. I put a retrofit on it the other days and it can with three cans of 12 oz. I put in two or most of two that would not even be close to filling an empty system, right?
It is not cooling but the compressure is coming on so at least the electrical system is working right?
Now I just have to see why it will not take Freon.
Any suggestions?
Pro
Joined: Jan 2006
Posts: 667
Likes: 1
From: Centennial Colorado
Did you try the diagnostic??? You may find your answer in 2 minutes..
http://www.idavette.net/tech/c4diag.htm
http://www.idavette.net/tech/c4diag.htm
Thread Starter
Heel & Toe
Joined: Mar 2004
Posts: 23
Likes: 0
From: Columbia SC
I pulled a vacuum on it for about 30 minutes and then attempted to charge it. The compressor is now engaging off and on on its own but will not stay on and does not want to take any more freon it is also not cool.
Using the AC manifold guages does the high pressure side of the guage need to be shut off to allow the freon to go into the low side?
Using the AC manifold guages does the high pressure side of the guage need to be shut off to allow the freon to go into the low side?
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Assume you are working with r12 and a 91 Vette? I believe it is a 2 lb system, meaning you do not have enough freon in the system to keep the low pressure switch from turning the power to the compressor/clutch off. By pass the switch temporarily with a paperclip and keep charging the system.
Thread Starter
Heel & Toe
Joined: Mar 2004
Posts: 23
Likes: 0
From: Columbia SC
I put a retro fit and am using 134a.
The other day when charging it seemed to release pressure out the the high pressure valve on compressor, why would this be? Could the system be clogged?
The other day when charging it seemed to release pressure out the the high pressure valve on compressor, why would this be? Could the system be clogged?
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Safety Car
Joined: Jul 2004
Posts: 3,840
Likes: 30
...if the system has been open for any length of time, the accumulator should be replaced as well as if it never has been replaced....while the system is apart, replace the orifice tube which is the metering device used for the evaporator.....if you can flush the system do so..if you had a compressor burn out, YOU MUST flush the system or risk successor compressor and system failure...place the system in a vacuum using a vacuum pump and proper gauges for an hour or better...this allows any moisture in the system to boil off, as moisture mixed with the refrigerant will turn to an acid and you will be no further ahead then when you started and most likely a great deal behind!....close all gauges and let sit for an hour taking note as to what the readings are on the gauge...if after an hour, the gauges have NOT moved, then you are ready to put the refrigerant and oil into the system....you will most likely have to jump out the low pressure switch to facilitate a faster draw of refrigerant into the system..
Last edited by Da Mail Man; Aug 13, 2007 at 09:45 PM.
Drifting
Joined: Feb 2006
Posts: 1,263
Likes: 0
From: CV ca
St. Jude Donor '11-'12-'13
Assume you are working with r12 and a 91 Vette? I believe it is a 2 lb system, meaning you do not have enough freon in the system to keep the low pressure switch from turning the power to the compressor/clutch off. By pass the switch temporarily with a paperclip and keep charging the system.
It sounds like it's short cycling on the low pressure switch.You did change the oil and flush the system before adding 134a?
Safety Car
Joined: Jul 2004
Posts: 3,840
Likes: 30
.........i just went through this..i reclaimed the refrigerant with my reclaim machine and tank and replaced a leaking high side shrader valve...i DID not change out the accumulator as the system was not entirely open and the valve replacement took only 45 seconds...
...when i pumped the system back down (as previously mentioned) and reintroduced the refrigerant back to the system, it appeared to take the charge but, possibly not all of it and i couldn't ram any more in to rated capacity and it sure as hell was not getting cold at all...i wound up replacing the accumulator (maybe it collapsed into itself) and replacing the charge and now all is well...the
end.....
...when i pumped the system back down (as previously mentioned) and reintroduced the refrigerant back to the system, it appeared to take the charge but, possibly not all of it and i couldn't ram any more in to rated capacity and it sure as hell was not getting cold at all...i wound up replacing the accumulator (maybe it collapsed into itself) and replacing the charge and now all is well...the
end.....
Last edited by Da Mail Man; Aug 13, 2007 at 09:55 PM.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
If you are retrofitting you should do like Da Mail Man says. And you must change the compressor oil, accumalator, orifice tube change is recommened, as is a system flush for any contaminates. If you blew refrigerant out of the pressure relief port you do have a blockage.
Thread Starter
Heel & Toe
Joined: Mar 2004
Posts: 23
Likes: 0
From: Columbia SC
I have done everything, flushed out all the lines, replaced the accumulator and flushed the compressor. The compressor seemed tight and was clean when pouring out the oil. Everything seems to be clear and free of blockages. I replaced the orfice tube, and put in 4ox of ester oil in compressor and 4oz in accumulator. New o-rings and pulled a vacuum and it held.
The system has taken in two cans of Freon but the compressor will still not engage. I jumped it and it runs. Could it be that the compressor AC clutch cycling switch is bad? How can I test the old one? When I unplugged it and jumped the plug the compressor engages, does that mean the switch is bad?
Everything seems to be all together and tight but the compressor will not engage. The green light on the dash is on now as it was not. I am at a loss!
The system has taken in two cans of Freon but the compressor will still not engage. I jumped it and it runs. Could it be that the compressor AC clutch cycling switch is bad? How can I test the old one? When I unplugged it and jumped the plug the compressor engages, does that mean the switch is bad?
Everything seems to be all together and tight but the compressor will not engage. The green light on the dash is on now as it was not. I am at a loss!
Last edited by rddaves54; Aug 22, 2007 at 12:33 PM. Reason: new message
