I was afraid I wouldn't have an answer for you. All I can suggest is if there is a separate AC condenser fan, it typically cycles on and off at the same time the compressor does but they usually have different relays. That will let you break the system into three parts, the compressor circuit, the fan circuit, and the controls they have in common. If the condenser fan, (or radiator fan), cycle on and off but the compressor does not, suspect the relay has burned contacts or the clutch coil has an intermittent break. More common would be corroded terminals in its connector.
The next suspect would be any type of computer module. I would need a wiring diagram to figure out which wire(s) to check, then I'd want to see what that voltage does when the compressor cycles on and whether that voltage cycles on again but the compressor doesn't respond.
Also be aware that testing system pressures can be misleading. A lot of the charge can be leaked out but as long as there is enough refrigerant in the system for some of it to remain a liquid, some of it will expand into a vapor making the pressures go right back up to normal. You would have to force the compressor to run, then the clue would be less-than-cold air inside and a not-very-hot condenser up front. You may also be able to jump the low-pressure cutout switch. It looks at pressure at a different point than where you attach the gauges. If that makes the compressor run, drain the system and recharge it with the measured amount of refrigerant. That is the only way to know for sure that it is fully-charged.
Wish I could be of more help. Think about reposting the question so the other experts can read it. Also include the engine size and your country if it isn't the U.S. I tried looking up your vehicle for reference and found three different engines and almost no other information.
Tuesday, February 5th, 2013 AT 4:18 AM