Compressor cycling off

My G.M.C. air conditioner, which was working perfectly well last week, is suddendy malfuctioning. The weather is hot and humid; the unit is set on medium cool, with the thermostat on high. Yet the compressor keeps shutting off: on for about 10 minutes, off for another 10, resulting in very little cooling. At that setting, and in this weather, it usually cools constantly, shutting on and off occasionaly at night when it's cooler. I'm recovering from surgery and stuck at home, so this is an Emergency! Any ideas?

: My G.M.C. air conditioner, which was working
: perfectly well last week, is suddendy
: malfuctioning. The weather is hot and humid;
: the unit is set on medium cool, with the
: thermostat on high. Yet the compressor keeps
: shutting off: on for about 10 minutes, off
: for another 10, resulting in very little
: cooling. At that setting, and in this
: weather, it usually cools constantly,
: shutting on and off occasionaly at night
: when it's cooler. Any ideas?

Is this a window/wall air conditioner or a central (or other) type?

It could be that the compressor is overheating and cutting out on its overload protector.

If a central type and the whole condenser is shutting down, there may be a problem in the contactor but the system should be checked to determine the actual cause.

Dan O.

Hi Dan,
It's a window unit. A friend checked the thermostat to see if it was causing the problem by wiring the two thermostat wires together; unfortunately, the unit is still cycling rapidly and hardly cooling at all. Do you think this is worth having fixed?

: It's a window unit. A friend checked the
: thermostat to see if it was causing the
: problem by wiring the two thermostat wires
: together; unfortunately, the unit is still
: cycling rapidly and hardly cooling at all.

Hi,

That would eliminate the thermostat as the cause which just leaves the wiring, the compressor components or it being absolutely plugged and needing a professional cleaning.

: Do you think this is worth having fixed?

If it's not a fault in the compressor itself (rare with the symptoms you described) and depending on the size of the unit, it very well could still be worthwhile to repair but will need someone to look into it more thoroughly. Unless it is a very simple problem (loose wire), it will likely cost at least $100 to correct.

The main problem as I see it is finding someone available to look at it. In hot weather A/C technicians are usually booked up for days in advance, if not weeks.

Dan O.