needing help with my 89 buick lasabre a/c. The compressor is not engaging,
no cold air, blower works.

I checked 25amp fuse and it is ok, I bought a refill kit and pressure reads
good. Also, this isn't the original compressor, I had it replace about 5
years ago.

Is there a relay or something else I can check? I there is a relay, where is
it, what does it look like. Is there anything else that can be easily
checked?

Everything seems to work except compressor doesn't engage. So I assume it is
electrical.

Thanks! Piedmont