1982 chevy k10 wiring?

[Rothwell]

ok i have a lifted 1982 chevy scottsdale wih a small block 350 v8 i have a 4 speend manual transmission my truck firts started eating threw starters i went hrew three in a month i was peeved but i could live with it but now im on my fourth starter and i cant get he ttruck to start anymore unless i push start it i want to know whats wrong and i want to fix it myself. i took it o a mechanic payed to have it looked at and he told me it was the wiring harness? i cant figure it out and he wont tell me much more, he told me i could get it fixed for a couple hundred bucks