whats the best way to test the components of the air con

switch the air con and the light on the switch works

fans under bonnet don't work thought 1 was for air con
whats the best way to test the pump could low/no gas cause both to maybe not working above

just get the aircon gas checked at halfrords or somewhere similar - it should be a free check.

It's more than likely low gas pressure, the aircon gas also contains oil to keep the pump lubricated so once the gas level/pressure drops below a certain level a sensor in the line shuts the system down, if you want to check the pump runs ok you can pull out the relay (in the engine bay fuse box) and just use a piece of wire to link out the contacts in the relay base, this will operate the compressor clutch and run the pump (you can see the AC pulley if you look in front of the drivers side front wheel), if you do this test don't run it for long, if the gas is low so is the lubrication and sustained running would damage the compressor

or you could just look at the air con compressor with it switched on to make sure the centre is spinning ?

(don't forget automatically comes on when screen setting is used)