I have a problem with Airmatic. I’ve had some problems previously, but I’m struggling to diagnose this one.

Last week I started to get the Airmatic warning light (car graphic with up arrow) and the message ‘visit workshop’. It came one 2 or 3 times but cleared each time and no noticeable reduction in ride height and the compressor did not seem to be running any longer than normal (suggesting no air leaks).

On Friday I got the ‘stop car too low’ message and the front and rear were down on their stops.

Now, all last week it has been getting increasing cold (coldest in many years) here in the UK, with the coldest day on Friday (about -6 to -10 deg C).

Current situation is
• The Car is down at lowest level, bottomed out on ALL four wheels
• I can hear the compressor cut in when I push the brake pedal (every 10th press or so), but only for a second or two then it stops (this has been normal since I’ve owned he car, 30 months now).
• If I try the various ride height settings, nothing, still bottomed out.
• Visit workshop (Airmatic graphic) comes on if you try to drive it away, but not the 'car too low' messge, even though it bottomed out
• I can hear ticking from each strut in turn (from memory this is what you hear if you change the ride height)
• I can’t hear any leaks

From what I read here and elsewhere, I think it could be:

1. Faulty relay
2. Faulty fuse
3. Bad wiring around the pump
4. The cold (and damp) weather
5. Faulty pump
6. Faulty control unit

Does anyone know the answer to any of the following, that will help me diagnose the problem:

A. Where exactly is the relay located, I think its called K67 but I can’t find it’s location
B. Where exactly is the Airmatic fuse (40A?), I think its in the passenger foot-well
C. I think others have said that the Airmatic pump is on the Driver side (this is a UK model, so RHS), behind a cover in the wheel arch, between the front of the front wheel arch and the front fender?
D. Does anyone know if extreme cold (and damp) weather can cause the air-lines or pump/actuator to ice up?
E. Given that the symptoms have changed (visit workshop message with no loss of height, then ride height too low with loss of ride height, now no message and no height at all) is it possible that the electronics (Airmatic control unit) could ‘lock-out’ requiring a workshop reset?
F. The compressor noise I hear sometimes when I touch the brake (static or driving), is this the same compressor that controls the suspension? I’ve always thought it was, if so, it’s working.

Any help with this would be greatly appreciated, I promise to document the root cause when I find it.

Thanks in advance

Chris