A/C indicator light is flashing...again....?

[sweetearth]

Two years ago, out of nowhere, the A/C indicator light began to flash and the A/C stopped blowing cold air. In the mean time, the weather got cold and I never got it fixed but my battery went out and I had to get a new one during the winter months. After that, the A/C started working again and worked the whole summer long until just yesterday when it stopped working again out of the blue...one second it was blowing nice cold air and the next it was flashing the A/C indicator light and blowing vent air. UGH! Anyone have any idea why this could happen. When I take it to the repair shop, I'd love to have a bit of knowledge. I'm wondering if possibly disconnecting the battery could reset the A/C again? Everything that's gone wrong on this truck has been some strange anomaly...HA! Seems the mechanic does more hair pulling than car fixing on this old guy! HAHA!

Ooops, it's a 1992 Chevy W/T truck.

[j cAT]

disconnect the battery negative connection for a time to reset the system. check all ground connections engine, battery , etc.

[brcidd]

Only 91 and 92 C/K trucks have an algorithm that counts compressor cycles- too many cycles in too short of time and it decides the system is low on refrigerant- and shuts down the compressor and flashes the a/c light for 2 minutes- to save the compressor. So, your system is probably working as designed and you have a major loss of refrigerant. Powering down the control head resets the control head and the problem will be redefined- and light will flash again- there was also a TSB on this years ago about inadvertant flashing light- and a way to wire around it.

If I were you, I'd pull the refrigerant out (with a reclaimer) and weigh it to confirm system is low- then I'd find and fix the leak-- number one leak location is the compressor shaft seal.

[sweetearth]

Originally Posted by brcidd

Only 91 and 92 C/K trucks have an algorithm that counts compressor cycles- too many cycles in too short of time and it decides the system is low on refrigerant- and shuts down the compressor and flashes the a/c light for 2 minutes- to save the compressor. So, your system is probably working as designed and you have a major loss of refrigerant. Powering down the control head resets the control head and the problem will be redefined- and light will flash again- there was also a TSB on this years ago about inadvertant flashing light- and a way to wire around it.

If I were you, I'd pull the refrigerant out (with a reclaimer) and weigh it to confirm system is low- then I'd find and fix the leak-- number one leak location is the compressor shaft seal.

If it has a major refrigerant loss then why would it work for an entire year without showing an indicator light flashing again? Seems like it should have gone out a long time ago if that were the case?

[brcidd]

If you determine it has tripped in error- then read and enact the TSB....