the 2000 XJ was the first year that coil pack was used; they quit using the distibutor.
Last year on a trip I went into some 3' deep water and the alt went out immediatly after I came out of the creek. I had to fix it on the trail 100 miles away from the nearest auto part store. It sucked....I ruined the whole trip for 3 other people. So in reply to waterproofing the alt...If I were you I would atleast spray some WD-40 all over and around the electrical output of it. I sprayed a coumpound called WIRE DRY over all of my electric points that are seen from the bottom of the Jeep. Wire Dry is designed for to reject water on electrical systems within boats (even works with salt water). Im not a member so I cant post pics, but if anyone want to see how I built my snorkel, just reply with your e-mail address. The snorkel looks as good, if not better than ARB's snorkel. It is made out of PVC pipe. Minimal welding required for mounting bracket. It costed all of 20$ to build.
Brian