ac recharge -- what am I doing wrong??
07-12-2003, 05:50 PM
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ac recharge -- what am I doing wrong??
I went to autozone and picked up an r12 -> r-134a conversion and recharge kit today. I vented all the r12 -- ahem.. safely.. -- and started the engine and ac. The instructions said if the clutch wasn't engaging, fill it with 1 can and let it set for 3 minutes.
Well, it seems to have not filled at all. The 1st can is still pretty much full, and the pressure on the guage was reading over 100psi -- far higher than it should ever be. The low pressure side is supposed to be between the evaporator and compressor, right? Which would be the one thats right by the strut tower and the new fitting would actually fit on to, right? Any clues what I've done wrong, or does my ac just have some kind of problem that a mechanic is going to have to fix? TIA
Well, it seems to have not filled at all. The 1st can is still pretty much full, and the pressure on the guage was reading over 100psi -- far higher than it should ever be. The low pressure side is supposed to be between the evaporator and compressor, right? Which would be the one thats right by the strut tower and the new fitting would actually fit on to, right? Any clues what I've done wrong, or does my ac just have some kind of problem that a mechanic is going to have to fix? TIA
07-12-2003, 05:57 PM
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Burning Brakes
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My low pressure connection is on the compressor, kinda on top. I believe that is the high side near the strut tower, but I could be wrong.
Also, the compressor won't engage without a certain amount of pressure in the system, and thus it wont take any of the freaon from the can. You need to disable the low pressure sensor I think to get the compressor to engage. I'm not sure how to do that.
Conor
Also, the compressor won't engage without a certain amount of pressure in the system, and thus it wont take any of the freaon from the can. You need to disable the low pressure sensor I think to get the compressor to engage. I'm not sure how to do that.
Conor
07-12-2003, 06:32 PM
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Burning Brakes
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Yes, the low pressure connection is on the drivers side in the wheel well, just follow the line back from the compressor. To bypass the low pressure sensor, unhook the wire to the sensor, which is behind the drivers side headlight, look down and the switch and wires all the way at the bottom on the AC line, that is the low pressure switch. Pull the wires off and jumper them together. Now you can fill the system. I would put one can in and check for leaks. I put a can in, and found a huge geyser of a leak from a cracked weld on the high side inlet..
07-12-2003, 09:21 PM
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Alright, got some pictures. I jumpered the sensor and put tried filling from the proper valve. No luck. I looked down by the clutch to see if I could find and test the ground but I'm not exactly sure what I saw.
<img src="http://boards.rennlist.com/upload/Img_0698.jpg" alt=" - " />
That wire hanging there wouldn't happen to be my clutch ground, would it? I kind of doubt it, but what else would it be? And where is the clutch ground? Can I get at it wouthout jacking the car up?
<img src="http://boards.rennlist.com/upload/Img_0702.jpg" alt=" - " />
Did I jumper this right? I assume I did, but if I didn't and thats why it's not working, I'd feel like a real idiot when I found out in 3 months.
<img src="http://boards.rennlist.com/upload/Img_0698.jpg" alt=" - " />
That wire hanging there wouldn't happen to be my clutch ground, would it? I kind of doubt it, but what else would it be? And where is the clutch ground? Can I get at it wouthout jacking the car up?
<img src="http://boards.rennlist.com/upload/Img_0702.jpg" alt=" - " />
Did I jumper this right? I assume I did, but if I didn't and thats why it's not working, I'd feel like a real idiot when I found out in 3 months.
07-13-2003, 02:02 AM
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Yes.. that is the exciter for the clutch. It needs to be connected. I would not bypass the switch. If your pressures are too high, and you happen to be filling from the high side, as you were, that can will explode.
That loose connection probably saved your hand, if not your life.
Vent off the remaing charge, connect the clutch exciter, and reconnect the pressure valve. Once you have done that, fill from the low pressure side.
That loose connection probably saved your hand, if not your life.
Vent off the remaing charge, connect the clutch exciter, and reconnect the pressure valve. Once you have done that, fill from the low pressure side.
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07-13-2003, 08:44 AM
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Burning Brakes
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The problem he is having, is it is completly vented and the clutch will not engange, thus not sucking in the gas. That is why they low pressure switch has to be jumpered, at least till he gets one can in..
07-13-2003, 08:49 AM
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If the clutch is still not engaging after jumpering the low pressure switch, it's time to do some electrical investigation. In the wheel well by the low pressure inlet, there is a wire for the clutch engager (mine had come disconnected and shredded by the clutch), you should have power up to that point with the AC on. You could also check to see if the clutch spins freely by hand.
07-13-2003, 08:51 AM
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Looking at your picture, again. The wire that is diconnected is the engager wire for the clutch. It plugs into that 2 inch long plastic covered wire next to it in the picture.
07-13-2003, 11:37 AM
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Hey stolarzj... did you read my post or skip over it?
Besides the exciter wire for the clutch... let's talk about the low pressure switch, and the proper way to recharge the system.
Bypassing the low pressure switch is not a smart idea. It is there as a safety. If you go running the compressor with no charge, chances are you'll burn it up. Most of the lubricating oil for the compressor is carried in the freon charge, so not having freon to pump means no oil circulation.
More alarming is that it also serves as a high pressure switch. When qconcept attached that full can of 134a to the high side, his pressures went all over the place. That switch could, and should, shut off the compressor. If not, the high side pressures will come up, and that can will explode. Believe it, it happens hundreds of times a year by shadetree mechanics. Many lose their hands and arms, others die. You are holding a 12oz grenade.
The proper way to re-charge a system, or convert in this case, is to take the car to a shop and have them evacuate the system. A flush is reccomended as well, followed by 2 hours on a vacuum pump. Once that has occoured, you can get your retrofit kit and add the proper (80%) freon charge of 134a and proper 4oz oil charge through the low side port. Add 1 can with the engine off, allowing it 15 minutes to enter and disperse. After that, start the car and the compressor should cycle. If not, it is safe to keep adding until you get to your weight amount in freon charge.
It is also reccomended that you replace the drier, expansion valve, o rings, and compressor oil when retrofitting.
AC system work is not too hard, but you must be careful. The elevated pressures they run at can be enough to seriously harm you.
Besides the exciter wire for the clutch... let's talk about the low pressure switch, and the proper way to recharge the system.
Bypassing the low pressure switch is not a smart idea. It is there as a safety. If you go running the compressor with no charge, chances are you'll burn it up. Most of the lubricating oil for the compressor is carried in the freon charge, so not having freon to pump means no oil circulation.
More alarming is that it also serves as a high pressure switch. When qconcept attached that full can of 134a to the high side, his pressures went all over the place. That switch could, and should, shut off the compressor. If not, the high side pressures will come up, and that can will explode. Believe it, it happens hundreds of times a year by shadetree mechanics. Many lose their hands and arms, others die. You are holding a 12oz grenade.
The proper way to re-charge a system, or convert in this case, is to take the car to a shop and have them evacuate the system. A flush is reccomended as well, followed by 2 hours on a vacuum pump. Once that has occoured, you can get your retrofit kit and add the proper (80%) freon charge of 134a and proper 4oz oil charge through the low side port. Add 1 can with the engine off, allowing it 15 minutes to enter and disperse. After that, start the car and the compressor should cycle. If not, it is safe to keep adding until you get to your weight amount in freon charge.
It is also reccomended that you replace the drier, expansion valve, o rings, and compressor oil when retrofitting.
AC system work is not too hard, but you must be careful. The elevated pressures they run at can be enough to seriously harm you.
07-13-2003, 03:23 PM
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The adapters that came with my conversion kit won't work for the low side. There is not enough room for the "quick release" end of the fill hose to attach. I think it is the alternator bracket that is in the way.
I was thinking if I could get an r12 fitting extension hose of some kind I could put the new adapters on the end of that, then attach it to the low side connection. Anyone know where I might be able to find a hose like that?
Or has anyone done something else that would work?
TIA
Conor
I was thinking if I could get an r12 fitting extension hose of some kind I could put the new adapters on the end of that, then attach it to the low side connection. Anyone know where I might be able to find a hose like that?
Or has anyone done something else that would work?
TIA
Conor
07-13-2003, 03:47 PM
#14
Three Wheelin'
If the system is taking the freon from the can slowly, put the can in a bucket of 100 degree water to raise the pressure in the can. Do not go over 100 degrees!!! Measure with a thermometer...no guessing!! When I did this, my system sucked in a 12oz R12 can in about 10min. Guessing when doing a/c will put you in a world of pain. Perry951 said it best, "You are holding a 12oz grenade."
07-13-2003, 04:40 PM
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Well, I parked with the car up on a low curb so I had just enough room to squeeze my head under and plugged in the ground. Got in and it blew the fuses, just like the PO said it would. I'm going to try to get in to the garage with the lift some time this week to replace just the ground wire. Would it be ok to ground it to the frame right by there rather than mess with that silly connection? Also, I checked and the compressor is turning freely so it's not seized. My guess at this point is either 1) (hopefully) just the ground wire needs replacing, or 2) the clutch is bad.
So.. If replacing the ground wire doesn't fix it, is there a source other than ebay where I can get a reasonably priced clutch? Does it have to be a Porsche oem part or is Autozone going to have a generic part that'll fit and cost a ton less? Or perhaps, if nothing else, a VW or Audi part..?
So.. If replacing the ground wire doesn't fix it, is there a source other than ebay where I can get a reasonably priced clutch? Does it have to be a Porsche oem part or is Autozone going to have a generic part that'll fit and cost a ton less? Or perhaps, if nothing else, a VW or Audi part..?