My refrigerant is low and a.c. compressor clutch will not engage, can I just add new refrigerant or do I have to make the clutch engage some how ???

 

If this is for an '88, is the system still partially charged with R12 or has it been converted to a retrofit refrigerant? That should be established before anything is added.

The low pressure cutout switch can be jumpered to briefly operate the compressor clutch.

Before doing that, however, see if the AC compressor hub can be turned by hand (engine off, of course). If the compressor is locked, further diagnosis is required.

It would also be good to connect the gauge manifold to see if there is ANY charge whatsoever. If not, the system should be evacuated, tested for leakage, refilled with refrigerant oil, and then recharged.

 

ok thanks I'll check it out later on

 

how will I be able to tell if the refrigerant was converted, I've only had the car for little over a year

 

There is no certain method other than sampling ad gas analysis. However, if you find SAE quick-connect fittings/adapters on the low and high side service fittings, it is a good bet that the system has been converted to R134A refrigerant.