A/C Compressor "locking up" intermittently

[Daytrepper]

Hi all;

Got the system all assembled today and charged.

Rebuilt RV 2 compressor and all new/restored components in the rest of the system.

I have 65-70* coming out of the vents, it is 94* out today and humid as can be so that seems like a reasonable temp drop, not snowing inside the car but definitely cooling.

Compressor was full of oil; system flushed, vacuumed and charged with 34 ozs of R134A.

Pressures are good 30-35 low side 150-170 high side, at idle.

Only issue I'm getting is the compressor will "lock up" from time to time, as if the clutch is slipping. Seems more of an issue at low RPM. It will be slow to start as well, as in, turn A/C on, it will "jump" for a few seconds then grab and start working normally.

It turns mostly free by hand, has some hard spots, but that is to be expected with the system fully charged.

I'm wondering if the clutch coil is weak or the disc is worn out; its a rebuilt RV-2 with an original clutch on it.

Thoughts?

 

[BLK 68 R/T]

I had a problem like that with a classic auto air install and it turned out to be a bad ground on my compressor. Added another ground wire from the mounting bracket to the negative on the battery and everything worked just fine after that.

 

[BLK 68 R/T]

I would also think that after the system runs for a little while, and has sufficient cooling going through the condenser and radiator the temps coming out of the vents should be below 50°. Maybe try putting a fan that moves a lot of air in front of the radiator if you’re just sitting idling while testing the AC

 

[vance.dykes]

when converting from r-12 to r-134 a the pressures are different than r-12 the low side should be around 40 to 50 psi . remember that pressure equals temp of air out put feel the low side lines should be cold the high should burn your hand as temp /pressure should be 175 to 250 . you might want to add a little and see what temp of air you get from the dash vents temp gage in the vent will tell more don't use a temp gun they read off.