Goldair2 180ah airconditioner not cooling.gas still full.how to check compressor?

Johan, there is no way to determine if the 'gas is still full' if the compressor is not running.....so it could be locked off on a low pressure switch because all the 'gas' is already leaked out.

If the contactor is pulled in when the thermostat calls for cooling, but the compressor does not run check for full voltage on the incoming side of the contactor as well as on the outgoing side of the contactor. If its going in and not coming out, the contactor is bad. If is coming out and the compressor is not running, look for a burnt wire first on the contactor then on the compresor dome. Look too for a burnt wire on the capacitor on the terminals marked 'C' and 'Herm'. Check to see if the capacitor is expanded or swollen up. If it is, it is shorted or open internally and allowing the compressor to overheat.

You probably need to call a competent repairman unless you are comfortable working with high voltage and capable of understanding basic wiring principles and able to follow the wiring diagrams to determine where the fault is.

Safety is no accident. You will be exposed to dangerous wire connections and should only trouble shoot with the power on IF you are competent around electricity.