In January of 2018 the accessory idler pulley froze and broke the belt. At that time I had the whole assembly [11925-AL50B] replaced along with both belts.

Now the A/C compressor idler pulley is screaming like a banshee, having used its last drop of lubricant, and it does NOT seem like a "WD-40 job" or something that can be "repacked" with whatever was in it, even temporarily. [DO correct me if I'm wrong, even if it just gets me a couple of days' use...]

My lizard brain is telling me just to cut that belt, as the A/C hasn't worked since I bought her in 2006. But I fear that would mess with the tension being put on the other pulley as they are mounted on the same shaft coming off the crankshaft itself.

Ideally, I could just buy a new assembly, have someone take the slack off the compressor belt, undo the assembly's three bolts, slap a new one in, re-tension the belt, and Bob's your uncle.

If that's the way it works, great. But I'm getting three different options (not counting the individual parts). Parts.infinitiusa only lists the 11925-AG30A ($158.87), Infinitipartsdeal has the "old" part number [11925-4W000] for $115.81, but says the identically-priced AG30A won't "fit my application" despite clearly listing it as the number that "superceded" the 4W000. Oh, and diagrams list it as "11925M", just for funsies, I guess.

I don't mind paying for the AG30A (if it works) and the install is easy (other belt booked in at 2.5 hours). I cannot find an image of ANY of these parts, however, and the parts diagrams don't help for reasons stated.

Thanks in advance for your help, and here's to hoping that I receive your wise guidance before the pulley grenades and takes its belt with it...

You're talking about the crank pulley and putting an odd load on that? No worries, cut that sucker off. Engines over the years have come with all sorts of belt configurations ranging from single to at least 4 that I've seen. The crank bearings are very robust and won't even have a clue something is different.

And lizard brain for the win. Thanks!