cherokee forum they have forums for other models to.  haven't been alot of expert advice there but there is a lot of "been there, done that" advice for things that are common on different models.
 could you be in between selections (p/t 4wd, f/t low, f/t hi, 2wd).  on my cherokee at least they are notorious for being screwed up on drive selection, almost all eventually need some sort of aftermarket fix.
Btw- as far as who makes what.  I've become convinced that they just take a truck around to all the auto manufacturers and load it up with left over parts,  from these they make jeeps.  I enjoy driving it, but when it comes to working on it, it is the most frankenstien POS I've ever turned a wrench on.