Rhensonsr

I replaced the AC compressor, low pressure switch, dryer, and vacuumed down, and installed 134 last year and the AC worked great. This year the AC was not blowing cold and the clutch was not engaging so I put one can of 134 into the system and the clutch began engaging, but it still was blowing hot air. Tried to put another can in the system and the compressor locked up, shut the ac off, and turned back on. The compressor started working again but still blowing hot air. Also, the second can is not being emptied. The low pressure is dropping to 20 lbs, and the high pressure is 290.

Thanks in advance,
Randel

billschroeder5842

You have a leak in your system.

This is one time I'd take it to a pro. When you did the work last year you may have not seated an "O" ring correctly. The pro will put dye in the system and check it for leaks,

Rhensonsr

Well, the problem is solved. Turned out to have a leak at the low port 134 conversion fitting, which allowed air to enter the system, the fan was not coming on which drove up the high pressure side, AND the low pressure switch was bad.

After thinking about things over night, I decided to start from scratch by opening the low side and letting the freon out to vacuum down the system since I found the conversion valve loose. As I opened the valve on my gagues, there was no freon coming out but plenty of air so I knew why there was only hot air. I vacuumed the system for 30 minutes, shut off the pump and isolated the system from the pump and it held -25lbs for an hour (leak fixed). 1 can went in easy but the 2nd can stalled about half way though with 22 lbs on the low side and 400 on the high side. I noticed the fan cycling but not staying on. The fan pressure switch did not come with the compressor I replaced so I grounded the wire to engage the fan. The high side dropped to 150 but the compressor shuttered when the low side dropped to 22. I bypassed the low pressure switch and the shudder went away. The low pressure switch I replaced last year was bad so off to Advance I go and $17 later, the shudder was gone, 2nd can emptied and the 3rd can took 1/2 of the can to get the temp to 34 degrees with 32 on the low side and 270 on the high. Finally, my wife will ride in the car again. Took me 6 hours but 4 and a half of it was saying "no way that switch is bad" and "there is plenty of freon in the system." Had I just started from the beginning (and not trying to save 2 cans of $4 freon), the process would have taken 2 hours but I learned a lot about my system.