First thing you have a "no crank' problem, not a no start.
now check that the small wire, at the starter, is normally ground (-) key off engine off.
now with the key at start, do you see power (+), at the small wire at the starter?
if you can switch the pos+ neg- signal, to the starter, with the key (and still no crank), you have a starter issue.
if you have a starter issue, remove starter.
if you have a starter that looks somewhat like the one pictured here (concentrating on the upper half (the other style looks nothing like this.))
remove three small bolts containing the solenoid, remove cover, plunger (clean up copper part of plunger) and spring. replace contacts shown here
put starter back together, reinstall starter, drive on.
HOWEVER if your starter looks like this
time for a real starter. NOTE the shape of the sol.
NOTE none of these starters are from a supra. images are a general idea of the actual configuration.
