[QUOTE=Adams' Apple]The system will need more than 10psi(running) to engage the comp. clutch. Most systems have the low pressure cut-off at around 20psi. Remember, too, that 134 runs at higher pressures/temps than R12. I'd say blow another can in it, and it should start to work.[/QUOTE]

Ok. I slowly got another can into it, but the comp. wouldn't start yet. Shorting to run, I got cold. Real hot lines to the rad and pretty cold on the other ones. Static (engine off) low side pressure was VERY high, and still showed very low when running. Next day, the compressor started ok like normal, but cycled every three or four seconds. Might be because it was pretty cool out. How do I know if I'm overcharging - my main concern, now that I know things are generally working as they should and I think I solved the slow leak? (the main dual connector at the compressor was not real tight so I snugged it up). Gonna be away from the computer this weekend, so I probably won't respond again until Monday. Thanks for all the advice - I'm learning as fast as I can

The only way to know if the system is correctly full is to put a gage on it. The 'static'(engine off) pressures on both sides(high & low) will be very close to what the ambient temp is. Example: If it is 75 deg. outside, your A/C pressures will be around 70-80 degs. They will be higher if the engine is hot from running. You might have a low pressure switch that is failing, or it may not be calibrated for use on a 134 system. Just an idea there.
I'd reccommend getting some gages on it, and see what's really happening.

[QUOTE=Adams' Apple]The only way to know if the system is correctly full is to put a gage on it. The 'static'(engine off) pressures on both sides(high & low) will be very close to what the ambient temp is. Example: If it is 75 deg. outside, your A/C pressures will be around 70-80 degs. They will be higher if the engine is hot from running. You might have a low pressure switch that is failing, or it may not be calibrated for use on a 134 system. Just an idea there.
I'd reccommend getting some gages on it, and see what's really happening.[/QUOTE]

Thanks. I'll pop the guage on the low side when I get home this afternoon and check it again, since it has had time to equalize and will be at ambiant temp. They didn't put a high pressure fitting on when they did the retro unless it's on the receiver/drier - which I cannot get access to. I can then, later, get a full guage set on it with adapters, as necessary. I just didn't want to hurt the compressor, or freeze up something.