Why wont 1988 Toyota pickup start?

Couple of things would look at: the hot wire and trigger wire going to the relay that you had to replace, plus, ecen though they're huge, I'd at least look at the voltage supply wire going to the starter. I'd actually ohm those wires to check for resistance caused by a melted/damaged area. You pulled a lot of juice when you smoked that starter and relay. One of the wires carrying that juice could have a weak area. I'd be checking all of the wires involved to see if you can find a bad area. I'd only take a couple of minutes to look them all over. The only other thing that comes to mind is one time years ago where I fixed a similar problem by cleaning the end of the hot wire that connects to the starter with a wire brush, just like cleaning the battery posts and clamps. It's like an invisible chemical barrier got built up. It visually looked fine but would not conduct worth a flip till I cleaned it. Pulling lots of juice one time does weird things like that. Clean the connection, where the starter grounds, the battery clamps.... You can do everything I just said in 10 minutes... Please post what you discover!