[davidlmitchell]

My late 2004 Honda has covered 92,000 miles. Previously when I turned on the air conditioning while the car was stationary, I'd hear a 'clunk' and the engine would slow slightly. This year the air conditioning failed. There is no cold air coming through, though the light comes on. There is no 'clunk' and the engine does not slow. The ducts blow air at ambient temperatures or slightly higher.
I've checked all the fuses - OK. I've checked Freon - it's fine.
I've swapped around the relays. They all work. This is bad news, yes?

 

[Flat Lander]

You covered all the basics. When you say you checked the freon, I assume since there's "no clunk", you checked it without the clutch engaged. If so, the pressures you read are inaccurate. You can only check them with the clutch engaged. Sometimes you have to remove the low pressure switch wire harness from the switch and install a jumper wire. This makes the A/C system think that the low pressure switch is closed (like there's enough freon in the system). Once you do that the clutch should engage then you can read accurate pressures to see if the charge is correct. Once the charge is good, you can restore the low pressure switch wire harness.

 

[davidlmitchell]

Impressive!

Let me check that!