A/c Troubleshooting

[mlonas]

I have a '98 Jimmy with an intermittent a/c (auto climate control). My a/c cools fine (45-50 degrees with ambient of 85) for a couple of minutes then the compressor drops out. I find that if I rev the engine to about 3500rpm then back to idle, the a/c blows cold again, but only for a couple of minutes. I had a mechanic friend evacuate the system and charge it to factory specs but the problem persists. I have cleaned the condensor coil thinking that a dirty coil might cause high pressure cutout. I can bypass the clutch cycling switch on the accumulator and the the system cools fine (which lead me to replace the switch thinking that it was not sensing pressure properly - no help). I don''t have any tech data so I''m at a disadvantage. Any suggestions would be appreciated.

[OUMike]

I have a '98 Jimmy with an intermittent a/c (auto climate control). My a/c cools fine (45-50 degrees with ambient of 85) for a couple of minutes then the compressor drops out. I find that if I rev the engine to about 3500rpm then back to idle, the a/c blows cold again, but only for a couple of minutes. I had a mechanic friend evacuate the system and charge it to factory specs but the problem persists. I have cleaned the condensor coil thinking that a dirty coil might cause high pressure cutout. I can bypass the clutch cycling switch on the accumulator and the the system cools fine (which lead me to replace the switch thinking that it was not sensing pressure properly - no help). I don''t have any tech data so I''m at a disadvantage. Any suggestions would be appreciated.

 

First of all welcome to the forum. I'm not that familiar with problems of that nature, but maybe try getting gauges fitted to your AC system. You may find the high side to be low? I don't think I've ever heard of anyone actually replacing the lines, but I know sometimes the fittings can wear out. I suspect a bad fitting could cause a problem of some sorts.