[oldskewel]

I had a similar problem on my '99. Professionals identified it as the compressor clutch. I bought a used compressor (with clutch) and was about to install it, but it turned out to be an electrical problem, so the compressor is still on my shelf almost 15 years later. The ignition switch, specifically, was the root cause, which is a known, recalled, defective part on those older vans.

So the tip is to at least consider that maybe the clutch is fine, but is just not getting the strong voltage it needs. Do you have a way to monitor system voltage while driving? A weak / failing alternator could be contributing.

Also, to clarify - you say "pulley area." Is that definitely the AC pulley, or could it be the drive belt tensioner, or even the alternator pulley? I had a random rattling in my 2011 LX which ended up being the alternator pulley (not the alternator itself, which is still doing fine).

 

[oldskewel]

My 2001, has the exact same symptoms, as OP. Do you mean, where the key goes, ignition switch, is causing the
rattle?
This has been going on for a couple of years now. My plan, when something "stops working", then should be
easy fix. ie. still on original alternator, air conditioner compressor. 212,000 miles).

For me, on my '99 EX, it was the ignition switch, PN 35130-s0x-305. That's on the left side of the steering column, activated by the key cylinder on the right side of the steering column.

And yes, as weird as it seems, that switch absolutely definitely caused the rattling noise in my AC compressor clutch. And when it was causing that problem, it was not causing other detectable problems that are typical of that failing switch.

That ignition switch is an electrical device. It switches things like the ignition circuit, starter, etc. It can burn, melt, and lose contact, primarily causing the car to just die (loss of ignition). I'm on about my 4th one, all but one of those was replaced for free by Honda on the recall / warranty. The one I paid for was before I knew the recall was unlimited.

I'm with you on how things are easier to find and fix once they fail completely. I think '99 was the worst of the years on this ignition switch thing. If you search on that part number I listed above, you'll find posts by me on here about how to very quickly open things up to inspect this part.

Like I said above though, I think the lesson from my experience is that a purely electrical problem could cause the AC clutch to act like that, whether it is due to a faulty ignition switch or something else.