Offroad-Express

Can nyone point me the right direction with a/c pump clutch not energizing! Is there a fuse somewhere hidden away?light comes on in dash switch.
How to check if gas has keaked out,I have a idea if system pressure is low ie no gas pump wont run?is this so?
any help much appreciated.

im pretty sure your correct that no gas pump won't run.

All sorted had run outta gas due to small leak at evaporator connection oring.