Hello
This is my first post

I have a UK S reg 1998 model Audi A4 1.9TDI 110 with Climate control.
My Compressor doesn’t turn on.
The codes out of the Climate Control Head are
C1= 22.1 – Compressor remains off until switch closes

C20=14.0 – A/C clutch voltage
C21=0 – Number of low voltage occurrences, non transient
C22=0 – Cycle condition of A/CRefrig High Pressure switch (F118)
C23=1 - Cyclings of A/C refrig High pressure switch
C29=75(little 5) - A/c compressor speed in RPM (engine speedx1.28)
C60= 5 - Temperature in C from ambient Temperature Sensor at fresh air blower (g109)

C52= 5 ( the little digit)
C53= 010


The temperatures do match up as it was done last night,
Note that it does this at higher temp as well so it’s not that I have dropped below the minimum air temp to turn on aircon.
The car is new to me.
To my knowledge the aircon has never been serviced.
I had a quick look with a UV light around the pipes and condenser apart from the compressor last night, every thing looks OK.

Does this car use an orifice tube?
If yes where does it sit in the car?

Having been taken for the “It just needs a regas” I am trying to avoid multiple wallet emptying, by doing some diagnosis first.

I haven’t taken a low or high side pressure measurement yet to see if there is any gas?
To me this looks as if the high pressure switch has kicked in- permanently.
This leads me to some options
1. The switch is faulty
2. The orifice tube is blocked
3. The compressor ports are blocked
4. Condenser is shot(although visually it looks alright)
5. This could be a red herring – the system is given fault codes that aren’t actually the problem.
The compressor doesn’t even try to click on.
I find it surprising that the gas in the low/high side hasn’t equalised to the point where the HP switch will close again- is this normal?
If any body has seen this fault sequence before I would be grateful if they could come forward and post there knowledge on it
Thanks
James Hughes