Fan clutch, AC compressor- somethings chirping?

2003 Ranger develops a shrill chirp, then screach often but with little reason. Seems to happen most at speed. Belt looked good, idler pulley felt loose, changed idler, no help. no drips at water pump, alternator seems fine. Could this be as sneaky as a fan clutch? If it could, how can I test it? Thanks.

If its a V6 Vulcan then its most likely the Cam synchronizer. Its located on the opposite side of the engine from the drive belts. The cam synchronizer took the place of the distributer and is about the same to replace. The camshaft position sensor sits on top of the synchronizer. Only have a OEM AKA Motorcraft syncronizer installed, because some of the aftermarket ones have had problem.

Here is a Link http://www.rockauto.com/catalog/x,carcode,1415168,parttype,10722

Thanks, and thanks for the link below. It is a Vulcan. Does the synchronizer have chronically bad bearings? Is there a simple way to test it? Sorry for all the questions this is my first underhood voyage in the post distributor world. Also there is no Check Engine Light, and the truck runs well, how much distributor function does this replace, my old rigs with a bad distributor/cap/rotor ran like crap?

Simply make a home made stethoscope with a piece of hose to pinpoint/verify the source of the noise.

The bearings I think are bushings, and when the bushings wear, get moisture,and rust inside it starts chirping. If the bushing wears too much it will ruin the camshaft position sensor from the shaft being wobbly, and give you a check engine light. If it is still ignored the Syncronizer will seize up and stop the oil pump from turning possibly destroying the engine.

It serves kind of the same function as the distributor in a indirect kind of way.

Replacing the Syncronizer requires a alignment tool, and you may also want to replace the camshaft position sensor as well, because it could be damaged.

The Syncronizer seem to start failing after around 90,000 to 120,000 miles

Thanks for the advice, I’ll get parts shopping tommorow.