Being a 2000, it would be behind the passenger front wheel. It's attached right under the exhaust manifold to the back of the block, the transmission bellhousing is notched with a rubber grommet for it. Easiest to jack up the front passenger, remove the wheel, pull the snaps for the plastic fender well on the back portion to pull it down out of the way. If you plan to replace it, make sure to get a Mopar sensor, 3rd party from Autozone, Advance, etc are flaky in these trucks and will often cause a misfire code on 1, 3, and 5, without an actual misfire. The sensor just doesn't read the flexplate fast enough, mostly a problem on the 3.9L V6, might not be as bad on the 5.2L/5.9L V8.

 

Yeah, it's just as bad on the v-8's. I always recommend Mopar sensors in critical locations, and the crank sensor is right at the top of the list.