what year vehicles interchange with an 2000 ford explorer alternator

Sounds as if you will be searching in a salvage yard. The personnel working there should have a cross reference guide. If they don't, but do have early model Fords on the lot, look up the part number for your vehicle, then check it against the year, make, and model of the vehicles they have. If the numbers match, you're good to go.

Look on rockauto.com to see what a new one cost from them-you might be surprised. (I was-my 1989 Crown Vic recently needed one.) I did a quick check and one for the 2000 Explorer with a V-6 is $78.00 (reman.(plus core deposit), and NEW ones for the same engine start at $100. (no core return required)