Oldsmobile/Buick Repair: electric problem with ac compresor, buick lesabre, pressure switch

Question
hi
i hve buick lesabre 1992,and ac compresor doesnt start to work.it works when i`m putting +12 volts on green wire that coming directly from compresor and going into the car
(inside).
What to check ,and why computer system doesnt start the ac compresor when it is set on 15 degrees.
thanks.

Answer
The compressor is protected by a low pressure switch, usually on the acumulator, that keeps the compressor from operating if the system is low on refrigerant, or if there is a restriction in the system that causes the low side to go too low.

Connecting some gauges would be the first step.

Van