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[Figureman52]

Hi, advice needed please.

Air conditioning not working, I have started the engine, aircon on Lo.
Relay K60 pulls in and the front two fans start.
The compressor does not start.
I am thinking that if the relay pulls in and the fans start then there must be enough pressure in the system.
If that is correct then is the only problem the connection to the compressor clutch?
Or am I missing something?
 Thank you.

[Nick W]

I would suggest it's the opposite: that the relay works and the fans switch on point to a compressor fault. The most likely compressor fault is not enough pressure in the system for it to work.

[LC0112G]

What you must not do under any circumstances (because it's irresponsible and will kill millions of penguins, and Greta will become very cross) is...

Find the low pressure filler port on the pipework, take off the plastic cap, and press the tit on the schrader valve with a thin plastic pokey thing (probably best to wear some thick-ish gloves). The gas in the system with the engine NOT RUNNING will be at about 2-3 Bar (30-45 psi) so similar to a pumped up tyre. If you can hear a hiss of escaping gas then there is probably pressure in the system (and you've just made Greta apoplectic) and you've got an electrical fault. If you can't hear the gas escaping then it's already all escaped so you'll need to fix the leak before getting it re-gassed. 

[Doctor Gollum]

Is ECO showing on the display?

If it is press it again and report back.

LO is merely a temperature setting and has the sum total of an empty beer can to do with whether the aircon is on or not.

[Figureman52]

Thank you for that. Nick W.

So what you are saying is that pressing the air con switch on the panel energises the relay which turns on the fans, but if the pressure switch in the system detects not enough pressure then the clutch does not engage on the compressor.

LC0112G:

So if I was to do what you suggested ( Which I didn't do Greta. ) and if I were to hear the escaping gas, the the problem is either the pressure switch, the actual connection to the clutch, including the possibility of a broken wire, or the clutch itself.

[Figureman52]

Is ECO showing on the display?

If it is press it again and report back.

LO is merely a temperature setting and has the sum total of an empty beer can to do with whether the aircon is on or not.

ECO is not showing, air con is switched on.

[Nick W]

Thank you for that. Nick W.

So what you are saying is that pressing the air con switch on the panel energises the relay which turns on the fans, but if the pressure switch in the system detects not enough pressure then the clutch does not engage on the compressor.

Yes. It's like that to protect the compressor.

[LC0112G]

LC0112G:

So if I was to do what you suggested ( Which I didn't do Greta. ) and if I were to hear the escaping gas, the the problem is either the pressure switch, the actual connection to the clutch, including the possibility of a broken wire, or the clutch itself.

I did not suggest you did that - I explicitly said you should NOT do that.

But the answer to the question is yes, some kind of electrical, wire or connector problem.

[Figureman52]

LC0112G:

So if I was to do what you suggested ( Which I didn't do Greta. ) and if I were to hear the escaping gas, the the problem is either the pressure switch, the actual connection to the clutch, including the possibility of a broken wire, or the clutch itself.

I did not suggest you did that - I explicitly said you should NOT do that.

But the answer to the question is yes, some kind of electrical, wire or connector problem.

My apologies 

So a good place to start would be to pull the plug off the pressure switch, bridge the contacts on the plug for a couple of seconds and if the compressor starts then the problem must be with the switch?

[LC0112G]

LC0112G:

So if I was to do what you suggested ( Which I didn't do Greta. ) and if I were to hear the escaping gas, the the problem is either the pressure switch, the actual connection to the clutch, including the possibility of a broken wire, or the clutch itself.

I did not suggest you did that - I explicitly said you should NOT do that.

But the answer to the question is yes, some kind of electrical, wire or connector problem.

My apologies 

So a good place to start would be to pull the plug off the pressure switch, bridge the contacts on the plug for a couple of seconds and if the compressor starts then the problem must be with the switch?

I've not done any electrical work on my Omegas A/C, so I'm not sure how many switches there are. On the Carlton there are 4 switches, two on the compressor and two on the pipework. Some are high pressure cutouts, and some are low pressure cut outs. Therefore difficult to guess what the Omega has, and whether they should be normally open or normally closed without a bit of research.

[Doctor Gollum]

Is ECO showing on the display?

If it is press it again and report back.

LO is merely a temperature setting and has the sum total of an empty beer can to do with whether the aircon is on or not.

ECO is not showing, air con is switched on.

just checking, as you wouldn't be the first to make that mistake 

Low pressure is likely the issue. Probably the condenser given that it's primary function is to stop the radiator getting dirty.