So the air con has suddenly stopped working the other day. There was no gradual drop off in cooling, it just blew out ambient air. I went through a lot of the posts in this forum and anything I could gather from the interwebs.

Symptoms:
The compressor clutch doesn't engage when I turn the A/C on.
Only ambient air is blown through the vents.
No squealing noise coming from the compressor or engine bay.

Does this sound like more than just a need to re-gas or something else?

I found this on the web about diagnosing compressor clutch problems on the UK Accord using the US Accord schematics (which looks identical to the CL9).

Except for testing if the relay is faulty, are the other tests safe to do?
What else can I check?

Thanks.