A|C help please!
Thread Starter
Drifting
Joined: Dec 2000
Posts: 1,785
Likes: 91
From: Leander TX
A|C help please!
I am trying to help out a buddy of mine vettenoob. We are trying to fix his A|C in his 86 and have his a stumbeling block. The clutch in the compressor is not activating when he turns on the A\C so we thought that it was low on collant. We hooked up a retrofit kit to it after having the system evaced and filled the system with R134a. After two pounds of collant the clutch still sat still, since you fill 134a at about 85%of r12 we stopped. We checked the electrical conector at the compressor and it was reading 8 volts with the A\C on. We are now thinking that the compressor and clutch system has gone bad. What do you think?
If it has gone bad we were thinking of changing the drier, both A\C lines, and the copressor\clutch unit. Is there anyting else we should change to make sure that the R134a works right? How about the condensor?
Please give any help because if we can fix this cheep he can use the money on mods instead.
If it has gone bad we were thinking of changing the drier, both A\C lines, and the copressor\clutch unit. Is there anyting else we should change to make sure that the R134a works right? How about the condensor?
Please give any help because if we can fix this cheep he can use the money on mods instead.
Racer
Joined: Aug 2000
Posts: 400
Likes: 0
From: Irmo, S.C
Re: A|C help please! (85WHITEZ51)
This may or may not help, but I recently went 6 mos. without air (and several trips to the shop) only to discover the connector that sits atop the compressor had a short or wasn't making a good connection. I zip tied the connector together tightly and all is well.
Jason
Jason
Burning Brakes
Joined: Mar 2002
Posts: 844
Likes: 11
From: Il
Re: A|C help please! (85WHITEZ51)
Most likey a low pressure switch. This is in series with the clutch. Like the previous post says, jump it out, turn on the air Max. Should have 12 volts give or take at the clutch. If you do this and still no voltage gheck back to the fan switch. If you have voltage and the clutch does not pull in give it a tap and see if it snaps in . If not your clutch is :U .
Le Mans Master
Joined: Jun 2001
Posts: 7,331
Likes: 518
From: Admit Nothing, Deny Everything, Make Counter Accusations.
Re: A|C help please! (85WHITEZ51)
You need to connect a set of manifold guages and monitor the high & low sides. You may have a problem with the low side switch or the compressor wiring, but I would need to know what your pressures are. Just charging without monitoring is a bad idea. I am not a fan of those cheapie retro kits. I prefer a full conversion.
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: A|C help please!
Thanks for all the suggestions. Here is an update as to what I/we have tried.
1) I tried to jump hi and low switches (connector), no compressor activity.
2) AC fuse in the fuse panel is good.
3) With AC control set to MAX, the plug at the compressor is reading 8 volts.
4) Bled the old R12 from system as recommended, changed the fittings as instructed, filled with 2 16oz 134a which included the oil.
The main reason a gauge was not used is because there was not one readily available. We just pumped the 134a into the system to see if the compressor would even come on (just cheapest way to determine if it was just low on R12). Any more recommendations would be greatly appreciated. If a gauge and readings will make resolving this easier, Im more than happy to get some gauges to facilitate this process.
[Modified by VetteNoob, 4:49 PM 5/16/2002]
1) I tried to jump hi and low switches (connector), no compressor activity.
2) AC fuse in the fuse panel is good.
3) With AC control set to MAX, the plug at the compressor is reading 8 volts.
4) Bled the old R12 from system as recommended, changed the fittings as instructed, filled with 2 16oz 134a which included the oil.
The main reason a gauge was not used is because there was not one readily available. We just pumped the 134a into the system to see if the compressor would even come on (just cheapest way to determine if it was just low on R12). Any more recommendations would be greatly appreciated. If a gauge and readings will make resolving this easier, Im more than happy to get some gauges to facilitate this process.
[Modified by VetteNoob, 4:49 PM 5/16/2002]
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Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: A|C help please! (VetteNoob)
You should have 12 volts or battery voltage at the compressor with the a/c on. If this is electronic air (C68) suspect the Blower Control Module. Check both compressor wires for an open first. Also, make sure that the blower wires haven't shorted. The Vette blower motor can draw quite a few amps and melt the wires. Check the connector at the blower too. If it's loose or corroded, it will heat up and melt the wires. As to the charge, you probably have air and moisture in the system now. You need to pull a vacuum before charging and on a conversion, the Drier should have been swapped out along with the o-rings and the system flushed. Static pressures (both high & low - clutch not engaged) should be about 50 lbs for most temps regardless of the charge.
Melting Slicks
Joined: Mar 2002
Posts: 3,252
Likes: 6
From: The Colony Tx
Re: A|C help please! (SunCr)
I am having a very SENIOR moment and can't remember what it is called, but there is sort of a plastic/screen thing that goes into one of the lines. If there was a problem with the compressor, or junk in the system this can get pluged up and cause a problem.
Sometimers disease is the pits. Sometimes you remember things, sometimes you don't.
Sometimers disease is the pits. Sometimes you remember things, sometimes you don't.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: A|C help please! (aj1988)
That's the orifice and if it was completely plugged the high side would skyrocket at which time the high side pressure switch would open (about 450 lbs) shutting down the system. Pressure readings will tell. Unequal static pressures are a sign of a plugged orifice.
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: A|C help please!
Ill try to report back on Monday or Tuesday with the pressure reading. Thanks for all the help and suggestions so far. Im sure this can be resolved with the help we have gotten from you guys so far. Thanks again.
Le Mans Master
Joined: Jan 2002
Posts: 5,320
Likes: 4
From: Kyle TX (Because Mojo Made me fill it in)
Re: A|C help please! (VetteNoob)
I put 12v to the compressor today from the battery. It ran for about 3 minutes and promptly started smoking. If it wasnt toast before, Im pretty sure it is now. What would have caused the compressor to spin up and start smoking? Could this be a result of low freon, bad clutch, or suggestions? Ill try to put a gauge on it either later tonight or Monday.
~VN
Will
~VN
Will
Le Mans Master
Joined: Jun 2001
Posts: 7,331
Likes: 518
From: Admit Nothing, Deny Everything, Make Counter Accusations.
Re: A|C help please! (VetteNoob)
I put 12v to the compressor today from the battery. It ran for about 3 minutes and promptly started smoking. If it wasnt toast before, Im pretty sure it is now. What would have caused the compressor to spin up and start smoking? Could this be a result of low freon, bad clutch, or suggestions? Ill try to put a gauge on it either later tonight or Monday.
You were probably running the compressor with no freon and/or no oil. This is why I posted above that you need to connect a set of gauges before doing anything.
Pro
Joined: Feb 2001
Posts: 662
Likes: 0
From: Denver CO
Re: A|C help please! (rbartick)
To start off, you need to vacuum the system down for AT LEAST 1 hour to remove the water after the proper repairs are done. OR you will have a waste of money and time. ANy GM AC system needs 6 oz. of PAG oil in the compressor, 2 oz. in the accumulator, and 2 oz. in the evaporator. The orfice tube NEEDS to be replaced, the accumulator NEEDS to be replaced. and a hose rebuild would be a wise desicion too. You need drain and flush all of the old oil out of the system too with an AC system flush. The cycling switch may need to be changed to accomodate the 134a.
Good luck,
Robert
Good luck,
Robert
Pro
Joined: Feb 2001
Posts: 662
Likes: 0
From: Denver CO
Re: A|C help please! (Bob Mosaic)
One more thing...
the pressure readings should be about 4:1 or 5:1
thus, a low side reading of 30 lbs should be accompanied by 150 or so on the high side.
you coil may be bad in the clutch. It is an electromagnet the pulls the face of the clutch in to the pulley face. If you replace the clutch you will need to set the air gap at about 1/16 of an inch. Be very carful when installing a new clutch, it is very easy to damage the snout of the compressor for a first timer. Also, what year do you have? I can get that compressor and clutch cheaper than anyone else. Also, i can rebuild the hoses and supply ANY AC component you could possible need far cheaper than anyother.
call me @ 678 849 6844 if interested.
Thanks,
Robert
the pressure readings should be about 4:1 or 5:1
thus, a low side reading of 30 lbs should be accompanied by 150 or so on the high side.
you coil may be bad in the clutch. It is an electromagnet the pulls the face of the clutch in to the pulley face. If you replace the clutch you will need to set the air gap at about 1/16 of an inch. Be very carful when installing a new clutch, it is very easy to damage the snout of the compressor for a first timer. Also, what year do you have? I can get that compressor and clutch cheaper than anyone else. Also, i can rebuild the hoses and supply ANY AC component you could possible need far cheaper than anyother.
call me @ 678 849 6844 if interested.
Thanks,
Robert