AC compressor not cutting on

1990 Volvo 240. The ac doesn’t work and about 6 yrs ago it was converted to r134a. How can I check it see whats wrong?

A/C systems really aren’t DIY things. They require specialized training and equipment. So the way to check is to take it to an auto shop that specializes in car HVAC systems.

You could check fuses, relays or whatever, but if you find something blown then you are just left with tracking down the reason it is blown.