A/C is driving me batty

[classicyuppie]

Recently got my '99 Beetle with the air not working and decided I could fix it myself. We were told by a local mechanic that the lines had no pressure and he would recharge the system for around $150. I figured if it was a simple recharge, I could do that myself and save a few bucks.

I purchased a recharge kit at AutoZone, double-checking the lines first just to make sure of the pressure reading. It read 0 psi. I connected the kit and followed the instructions, eventually bringing the charge up to around 55 PSI as recommended by the instructions. The a/c was running full blast as I was told to do. Hot air just kept spewing out into the cabin.

I've checked the compressor and it's kicking on. I can hear it engage when the a/c switch is pressed on the dash. I tried putting the air on defrost as recommended by the owners manual - nothing. Tried turning Diablo off then on again after letting it sit for a few minutes - nothing. I also tried driving it around for a bit with the a/c on - nothing.



I'm really wanting to get this working myself. I'm thinking either it's a bad a/c clutch or the fan control module. I'm new to car repair so I'm hesitant to try a bunch of different things, with the fear that I'll break it more or worse - damage something else in the process.

It's pretty steamy in the midwest around this time of year, with several days over 100 degrees with the heat index in Indiana. Any help would be appreciated.

[Supercharged98]

There is one thing they don't put on the recharge cans, when the pressure falls to zero, don't use this product. When the "sealed" A/C systems falls to zero psi, it means you have a leak and and it's not a sealed system anymore. Moisture can get in and ruin everything. You need to find the leak, using dye and a backlight. Repair, vacuum the system down, add freon with oil,add then top off with freon to the specs. Which is......
High side= 232# max
Low side= 25-35# minimum

[classicyuppie]

Originally Posted by Supercharged98

There is one thing they don't put on the recharge cans, when the pressure falls to zero, don't use this product. When the "sealed" A/C systems falls to zero psi, it means you have a leak and and it's not a sealed system anymore. Moisture can get in and ruin everything. You need to find the leak, using dye and a backlight. Repair, vacuum the system down, add freon with oil,add then top off with freon to the specs. Which is......
High side= 232# max
Low side= 25-35# minimum

I agree, which would have been *very* helpful to know that last night, sweating my butt off to charge it (oh, the irony).

I looked on the ground to detect any leaking fluid during and after the recharge, but I didn't see anything at all. I don't know if it's that easy to tell or if using a dye/blacklight kit is a must for detection. Like I said, I'm new to this.

I'm thinking that if the system has a serious enough of a leak, to just take it in and have them overhaul the a/c system and restore it to new. That's a bit beyond my capabilities.

One thing I can say is that when my wife was sitting behind the wheel, she did feel short (*very* short) bursts of cool air coming from the vents. I don't know if that means that outside air has gotten into the system. One thing I also forgot to mention was that that pressure on the high side read around 20 psi, which based on what you put seems rather low.

[Supercharged98]

You'll never see the freon leaking. When it excapes from a sealed system, it turns to a gas. That is why you have to add a dye to the gas, when the freon leaks it deposits the heavier dye droplets when it excapes from.

If you are using a freon can with a gauge, you are reading the low side. Freon is added to the low side or suction line of the system. If it's reading 20lbs, you're a little low on freon. When you turn the A/C off and let it depressurize, the static pressure should be somewhere around 100 lbs. But, don't go by that.

You might luck out and add a little more freon and it will run ok for a while. I had a car that it would run from spring until winter and then leak out a little when it got too cold out.

If you want to try to save a lot of money and fix it yourself, you can buy the dye at Autozone. It will show up when it leaks down. And if you want to repair the leak, most things are easy to replace, most of the time it's a o-ring at a joint connection.

You can buy a inexpensive vac pump from Harbor Freight Tools. We bought one that runs off of a air compressor and makes enough vacuum to repair A/C systems in cars.

Good luck.

[jason m]

To repair it yourself it will require purchasing or renting a vacum pump from auto parts store (autozone has a tool loaner program) dye, blacklight, R134a refrigerant, oil charge, and a little sweat. First if the pressures were at zero the compressor will not kick on. You will need to bypass the low pressure switch. Put in a can of oil charge (to protect compressor) refrigerant, and dye in and run for about 15 minutes or so. Let it sit for an hour or so and go check for lks with blacklight. Check all schraeder valves and connections in ac system. Once all lks are located repair as needed (normally o rings) and replace the accumulator/ drier assy ( this will absord moisture in sytem) hook up vacum pump and bring to vacumn for at least 30 min. Should hold vacum very close to 30". Now fill with another can oil charge and refrigerant. You will most likely spend close to $250.00 on parts and spend a few hrs. If you are rethinking this is the time to do it. You can take to firestone and have the ac checked out for about $35.00. and Know how much they wil charge you to repair.

[classicyuppie]

Originally Posted by jason m

To repair it yourself it will require purchasing or renting a vacum pump from auto parts store (autozone has a tool loaner program) dye, blacklight, R134a refrigerant, oil charge, and a little sweat. First if the pressures were at zero the compressor will not kick on. You will need to bypass the low pressure switch. Put in a can of oil charge (to protect compressor) refrigerant, and dye in and run for about 15 minutes or so. Let it sit for an hour or so and go check for lks with blacklight. Check all schraeder valves and connections in ac system. Once all lks are located repair as needed (normally o rings) and replace the accumulator/ drier assy ( this will absord moisture in sytem) hook up vacum pump and bring to vacumn for at least 30 min. Should hold vacum very close to 30". Now fill with another can oil charge and refrigerant. You will most likely spend close to $250.00 on parts and spend a few hrs. If you are rethinking this is the time to do it. You can take to firestone and have the ac checked out for about $35.00. and Know how much they wil charge you to repair.

That's something to think about. Thanks for the detailed information. I don't think I'm that comfortable with working on the a/c system in that much detail yet. A simple recharge is one thing, but anything more involved and I'm more inclined to plunk down the money to have a "pro" look at it.

Question though... if I charged the system last night and there's a leak in the system somewhere, when I check the pressure again today, it should read back at 0 psi, correct?

[jason m]

Originally Posted by classicyuppie

That's something to think about. Thanks for the detailed information. I don't think I'm that comfortable with working on the a/c system in that much detail yet. A simple recharge is one thing, but anything more involved and I'm more inclined to plunk down the money to have a "pro" look at it.

Question though... if I charged the system last night and there's a leak in the system somewhere, when I check the pressure again today, it should read back at 0 psi, correct?

It depends on how bad the leak is.

[D2Beetle]

Before you spend any big bucks on it; have you read this Thread?

[classicyuppie]

Originally Posted by D2Beetle

Before you spend any big bucks on it; have you read this Thread?

I'm even more confused after reading that post. I'm not very good with electrical systems but here's what I know. About 5 days after filling the a/c lines with freon, the pressure went from 0 psi to 55 psi and have stayed at 55 psi consistently. Fact: there is no pressure loss in the short term so therefore any line leak that *may* exist is at the least a very minor one. I'm more concerned with actually being able to blow cold air through the ducts.

I've changed the cabin air filter (hadn't been changed since the vehicle left the factory!) and all the fuses have been checked as well.

[MyOtherRidesAVette]

I might suggest that you go back and re-read this thread
A/C takes a long time to cool, but when it does it works fine.
and the links contained within. You probably have to a small degree, but I doubt you REALLY read thru it. It will give you a much clearer insist into the system and ALL the potential issues with any system that is not maintained properly or correctly.

There is also another thread that gives even more reading links and details. I'll see if I can find it and put a link to it up also.

MORAV.