Then "cheat."
First research what it should be running for temperatures and pressures and see if it will run long enough to see what you have. If it seems high, dump a small amount of refrigerant and see if the pressures/ temps come into line. Learn to measure suction (low) side superheat. This will help tell you if system is over-charged. You measure low side pressure and look at the gauge / chart to convert that pressure reading to R12 satureated temperature. You measure the temperature of the low side line while operating, with a probe and wrapped with insulation or rag at the probe. This then gives you TWO temperatures-------the one you measured and the converted temp/ pressure off your low side gauge. You subtract those two readings and that is superheat. You want AT LEAST 15F difference and typically more like 20F
If you can find R12, and you can even find it around here........and I don't mean this aftermarket crap with LP (propane) mixed, I mean REAL R12 you can cheat. Vent what is there, and "rig" with fittings and your gauge manifold to hook up to intake manifold vacuum. Adjust the engine for highest vacuum, IE play with timing and idle speed. You will likely not get more than 20" Hg. Evacuate the system, Charge a small amount of liquid into the high side, to 'sweep' through the system, and re-evacuate only on the low side. Then recharge.
Now if you are thinking that the compressor is bad regardless of charge, maybe bad bearings, scored cylinder/ piston, etc, you can also force it to run long enough to "feel out" how it's doing. Prepare to jumper power to the clutch as you did before, and dump the charge. Then jumper and run the compressor ? 10 seconds long enough to get a feel. If it seems rough and or drags the engine way down, I'd say the compressor is likely done for.
THIS HOWEVER does not compute with a bad clutch. There is no reason that a bad compressor (bad internals) would cause a high electrical drain on the clutch. Either the clutch is drawing a lot of current because the clutch is bad, or the compressor is dragging down the engine because the compressor has problems, but the TWO should be separate issues.
Then "cheat."
First research what it should be running for temperatures and pressures and see if it will run long enough to see what you have. If it seems high, dump a small amount of refrigerant and see if the pressures/ temps come into line. Learn to measure suction (low) side superheat. This will help tell you if system is over-charged. You measure low side pressure and look at the gauge / chart to convert that pressure reading to R12 satureated temperature. You measure the temperature of the low side line while operating, with a probe and wrapped with insulation or rag at the probe. This then gives you TWO temperatures-------the one you measured and the converted temp/ pressure off your low side gauge. You subtract those two readings and that is superheat. You want AT LEAST 15F difference and typically more like 20F
If you can find R12, and you can even find it around here........and I don't mean this aftermarket crap with LP (propane) mixed, I mean REAL R12 you can cheat. Vent what is there, and "rig" with fittings and your gauge manifold to hook up to intake manifold vacuum. Adjust the engine for highest vacuum, IE play with timing and idle speed. You will likely not get more than 20" Hg. Evacuate the system, Charge a small amount of liquid into the high side, to 'sweep' through the system, and re-evacuate only on the low side. Then recharge.
Now if you are thinking that the compressor is bad regardless of charge, maybe bad bearings, scored cylinder/ piston, etc, you can also force it to run long enough to "feel out" how it's doing. Prepare to jumper power to the clutch as you did before, and dump the charge. Then jumper and run the compressor ? 10 seconds long enough to get a feel. If it seems rough and or drags the engine way down, I'd say the compressor is likely done for.
THIS HOWEVER does not compute with a bad clutch. There is no reason that a bad compressor (bad internals) would cause a high electrical drain on the clutch. Either the clutch is drawing a lot of current because the clutch is bad, or the compressor is dragging down the engine because the compressor has problems, but the TWO should be separate issues.
