Try replacing the ballast resister and putting di-electric grease on that contact plug under your column. You cannot jump these made in mehico starters too many times or they will need opened up reworked. Too many clunks and they won't engage. I had this same problem with mine. Auto 3 on the tree. I replaced the starter twice, replaced the coil wire, ballast resistor, starter relay, ended up being a undervolting alternator, and bad 40 yr old wiring. 40 yrs of impedance.