Hello, After a month of sweating it out, I now have air conditioning once again, but something appears to be wrong: the compressor runs constantly whenever the A/C is on. Known quantities: 1) The system has a small leak somewhere - it loses enough refrigerant to stop working after approximately 3 months. I'm working on finding the leak, which is why I'm charging it up. 2) I charged the system yesterday and noticed that the compressor ran constantly. Thinking that somehow I overcharged it, today I recycled the refrigerant, evacuated the system to 29 in-Hg for 30 minutes, held that for another 30 minutes (did not lose a bit of vacuum), then charged the system with 2.0 pounds of R-12 (purposefully undercharging it initially to see if it would cycle more frequently). The air at the center vent is cold (40 deg. F when moving, around 60 when sitting), but the compressor still does not cycle (at least, as far as I can tell; I do have Fanzilla, so it's tough to tell if it's cycling when I'm moving). 3) The ambient temp. is a humid 90 degrees F and my cooling fans are running constantly with the A/C on. Pressures from the manifold gauges are... rest pressure: 69 psi (low and high) @ idle: low side: 42 psi high side: 155 psi @ 2500 RPM (car not moving): low side: 28 psi high side: 206 psi 4) My orifice tube, accumulator, high and low pressure switches were replaced 4 months ago when the system was last recharged (and I'll replace the accumulator and orifice tube again when I open it up to replace whatever is leaking). As far as I know, everything was working and the compressor was cycling normally the last time around, therefore, I don't suspect faulty switches (I didn't have gauges then, so I don't know the pressures). Section N:09 of the good book seems to point to a faulty orifice tube, clogged compressor inlet screen, or overcharging. Given my data, could that be right? I tested the calibration of the tank scale this morning, so I don't think I'm overcharged (especially since I only put 2.0 pounds in). Any advice on how to proceed would be greatly appreciated. Thanks! Travis Graham #6344 To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/