I have been reading every post I can find and everything I can find on the net, but still need help. Please help with my A/C.

My a/c was blowing hot, so I took it to the shop. They vacuumed it and it held. They charged it with r-12 and it showed no leaks. They kept it overnight and it showed a slight leak in the condenser and compressor, so they removed the r-12.

I just wanted it to last through the summer so charged it with freeze-12, because I didn’t know I could get r-12 on ebay. I put in about 1 oz of the oil that came with it, and STOP LEAK. After the second can of freeze-12, my a/c started blowing cold. When the vent temp got to 50*, the compressor sounded like it was working harder and the vent temp started to rise back up to 85*. The low side pressure rose to 90 psi.

I had the freeze-12 removed and used a venturi pump to vac the system. I then added 24 oz (2 cans...and I know that is not enough) of R-12. The compressor cycles and the vent temp cools until it reaches 45*. Then the low side pressure starts to rise ( 75-90psi) and the compressor stops cycling and stays on constant, but the air starts to blow warm. The compressor sounds taxed when the pressure gets high. I don’t want to add the rest of the r-12 until I know why the low side get so hi after the vent blows 45*.

When I let the car sit for a while, the low side pressure drops to 45-50 psi, and when I start the a/c it will blow cold (gets to 45*) until the pressure rises again (usually 5 mins or less).

I know the correct way is to have the shop replace the compressor, accumulator/dryer, and condenser, flush and fill. However, I want to do it myself. Please help. Thank you…..jster

 

Just another piece of the puzzle:

I drove the car today and the a/c vent blew 40* in NORM the entire 1 hour trip. The outside air temp was 70*. Could this be an electric cooling fan issue?? I have the 2 fan setup and neither one was operating when I had the problem.

 

Those fans need to be on. At least one fan should always be on when the A/C is on.

I believe that the 1988+ cars, the passenger is controlled by both the fan switch and the A/C pressure (high side). The 1987 and earlier being controlled solely by the fan switch.

If you don't have a cooling fan running with the A/C on, the pressures will be sky high from an overheated condenser. The fans will turn off above 40 mph since they impede air flow from the air dam at these speeds. This would explain why your A/C worked fine while driving down the highway. (Condenser being cooled by air rather than fan)

I'd get the fans fixed before tackling the A/C.

 

well first... i would recommend a retrofit to r134a as it will save you money. sounds likes you have a blockage in the system somewhere, more than likely its the orifice tube, you can try to replace it, and see if that helps, but i would first try to fix the leak that was found otherwise the system is not going to work for long, you need a 100% sealed system. and another thing, you should never just add oil to the system unless you know it needs it, too much oil in the system will cause insufficient cooling, and an overheated compressor which can costs you lots of money in replacement. the oil in the system will never leak out, it will always be in there, the only time that it will need more is when you replace lines or parts of the system.

if after replacing the orifice tube you have the same problem, you should flush the system, you can do this yourself with a/c flush and compressed air. replace the oil in the system, vacumm the system for a minimum of 30 minutes, see if the pressure holds for 24 hours at around 29.7hg. if it drops any you need to find the leak. if it holds, recharge the system.

 

Reid: Thank you. I will trouble shoot those fans today. I will post what I find out.

Quick Style: Thank you as well. I know 134 is cheaper, but I really want to keep it R-12 right now. I hear that soon, (possibly as soon as next year) 134 will die the same death as R-12. I don't want to retrofit twice if I don't have to. I will spend the $60 for the R-12 and with no leaks it will last for years. This is the first time since new (21 years) that it leaked.

Thanks again guys.....jster

 

Update...

Reid, you were right! The aux fan is not working.

I jumped the A-B terminal in the ALDL, disconnected the high pressure switch and turned the a/c to NORM, MAX, and BI-LEVEL, with the motor off and the key on. I heard a relay click when I put it in an a/c mode, but neither fan turned on.

Now I have been reading posts on fans. I hope to find the solution soon. Thanks for the help......jster

 

After tons of research on the cooling fans, and tons trial and error, I DID IT!!!

The wires that go into the connectors to the fan relays had bare wire showing. They did not look like they were touching, so I didn't think that was my problem, but it was.

For some reason, the insulation pulled back from the relay connectors and exposed bare wire. Yesterday, I taped the exposed wires and the fans work as advertised.

Now my a/c blows 43* even when I'm stopped. Also, I watched the fans turn on exactly when they are supposed to. I will put the rest of the r-12 in tomorrow. I bet the freeze-12 would have worked as well, if my fans would have been working.

On my above post, the clicking I heard was not at the fan relays, it was the compressor clutch. Once I found the fan relays, I noticed the bare wires and started the troubleshooting.

The tape on the relay wires if just a temporary fix. I am trying to find out how to fix it permanently. If anyone knows how to do that, please let me know.

Thanks again......jster