Ok so it's not really a cricket, at least I don't think so, but I do have an almost chirp like sound inthe engine compartment on the passenger side. I'm certain it's somthng belt driven, but I cannot narrow it down. I changed the water pump about a year ago, and both the idler and tensioner pulleys about 2 weeks ago. It starts when the engine starts, goes away at higher rpms, returns when I'm idling at a stop light, and ends when the engine is shut off. It's worse when the van is in gear, versus when in park or neutral. On a side note, it seems as if i'm getting low on freon, I do not know when it was last re-charged. Any help would be most appreciated.

take off belt and run for a few seconds to see if noise goes away. if so, then go onto checking moving parts like a/c pulley, alt etc. buy yourself an electronic ear from harbor freight and you can really pin point where noises are coming from

not your problem but I had a chevy truck that had a really annoying chirp. problem was a cracked power steering pulley

It is definitely something belt driven. I think it might be the ac clutch. It squeals really badly every once in awhile when we turn the ac on. Is there a way to test it, becasue from what I can tell it's a rather pricey part and I don't want to spend money if I do not need to.

If it is the ac clutch, what would be the best way to change it out?

did you investigate the alternator? before you post back, SEARCH this forum for Alternator issues!!!!!

when you engage the a/c you put more load on the electrical system (alternator)

you also MUST pull off the belt and do some hands on feel for diagnosis.

the BEST way to fix the a/c clutch is to have someone with the proper tools make the repair. if you don't have the right tools it will cost you 2-3x as much as if you had someone do it correctly