Hydraulic Pump running at switch on

[Pete Somers]

The accumulator is to keep the doors closed while the a/c is on the ground with no power on. If the doors stay closed ok the accumulator is ok.
If you have not used the a/c for a week the pressure switch may be a little sticky. Also a low battery will not allow the pressure to build up to shut off the motor.
Before you start the engines pull the gear c/b and push in after you have started and see if the pump run ok then.

Pete