[electro]

Recently, a question was asked:

"I had the system charged last summer. Tried it today and it blew hot air. The compressor was cycling on and off quickly so I put a gauge on it. It said it was OK but I dumped a bit of refrigerant in to be sure. Still blows hot air.....Any ideas? BTW the compressor kicks in for about two seconds and then kicks off. HELP!"

 

[Boghog]

Short cycling of the compressor is an indication of low refrigerant. There is usually a pressure switch located on the low side line. 2 wire switch. If you jump the terminals together and the compressor stay cycling your low on refrigerant. I would use a set of 2 gauges and monitor lo and hi pressure while adding refrigerant. There should be a label under the hood that states the capacity of the a/c system do not exceed the amount.

 

[electro]

When an A/C system is low, the refrigerant oil does not return to the compressor very efficiently. As well, the returning refrigerant is not cold. These factors as well as the short cycling mentioned above by BogHog, will cause the compressor to overheat, and ultimately fail.

A low system has a leak. It may be very small and not findable. One should consider using dye when recharging. If that system again looses charge, the dye may well illustrate the location of the leakage. Dye don't lie.
Any large leaks should be repaired immediately. Once a system has been repaired, remember to evacuate the system for at least 30 min.