R & R A/C compressor

I've tried recharging without any positive results.. Now compressor won't engage unless switch at accumulator(low pressure switch?) is jumpered to ground.. Then when compressor cycles and low side reads about 40 psi, I still don't get cold air.. Does this sound like a compressor gone bad?

If so, any specific tricks when changing it out besides bolting it in and hooking up the new one.. Does oil need to be added or the system vaccumed out?

Thanks,
William

I've tried recharging without any positive results.. Now compressor won't engage unless switch at accumulator(low pressure switch?) is jumpered to ground.. Then when compressor cycles and low side reads about 40 psi, I still don't get cold air.. Does this sound like a compressor gone bad?

If so, any specific tricks when changing it out besides bolting it in and hooking up the new one.. Does oil need to be added or the system vaccumed out?

Thanks,
William

William, if your low pressure switch needs to be jumpered to get the compressor to engage, you're likely low on refrigerant. To me, it sounds like you don't have a full set of gauges, REQUIRED for real AC work; because if you had those, you can read and post both high and low pressures at 1500 rpm with compressor engaged. What does your static pressure (non-engaged compressor) read (high and low should be the same with that) ? Without pressures one cannot provide any help to you. If the compressor does engage and turn when you jump the switch, the compressor itself may not be bad. If you are truly low on refrigerant, you must find the source of the leak. I'd recommend an AC specialty shop for this, as an electronic leak sniffer tool is utilized. Another way is with a full refrigerant charge and use UV-dye.

If the compressor itself is truly bad, then the remaining refrigerant needs (by law) to be revovered (more equipment). However, if the refrigerant has leaked out, then bolting on a new compressor is just that, with using the new seals provided with it. One usually measures the amount of oil that can be drained from the old compressor and adds that much plus 2 ounces, then spins the compressor (not just the pulley) by hand a few revolutions. If the refrigerant has leaked out, moisture will get in, so most often a new accumulator is also installed, and usually a new orifiace tube because they're cheap, and one can observe if there's any particles caught there. After that, a good vacuum gets pulled for maybe 45 minutes (more equipment), then the valves closed to see if it holds vacuum for 15 minutes, then the correct amount of refrigerant is added by weight (using more equipment). If you don't want to rent, buy, borrow this equipment, then just bite the bullet and take it to a shop to be fixed. Or wait until March 2010, summer willbe over in LV by end of October...