Well, according to the Super Legends game, he became an archaeologist.
We also know that, at one point, He and Rita had a child, which eventually became Thrax, the villian in the 15th Anniversary episode "Once a Ranger." As for the Super Legends Game, He was an Archaeologist, but then became his old evil Lord Zedd self again, using Time Crystals to mess up with the time line. Said Crystals end up traping him in a void outside of time, never to be seen again. This, mind you, is rather debated amongst fans as if it should be taken as canon or not.