Oh I see, you want to swap out the compressor...when you said comp I thought you meant computer!
Mine isn't the best to test the compressor on as I run LPG and the tank is where the spare wheel would be, and the Compressor has been moved so requires a bit more dismantling of the car to get to it as it now sits in a recess under the rear seat floor and is a fiddle to get at!
Take your compressor out and plug 12V into it and see if you can stop the air flow with your thumb, you should not be able to block the air and it should lift your thumb of the pipe on a cushion of air....
Sort it for him Ant, lad must be distraught if it has given him Alopecia.