transmission wiring

Need help, sold my fsm with my xt. I now have a 1990 loyale wagon 4eat all wheel drive, the story goes bought wagon, rear diff blown up and cought on fire, r&r diff with used, correct ratio, drive car severe tourque bind always, even with fuse in, test all soloinds good, check tcu pinouts,tcu internal short always applying duty c soloind, r&r tcu with junkyard unit, works fine for 3 years, sold xt and manuals. Now loyale locks up tourque converter randomly, will do it cold, at idle, foot on brake, from park to reverse, nuteral to drive. Its locked up enough to kill the engine, somtimes it will work fine, no rhyme or reason. I think its electrical, changed tcu again same prob. has anybody else seen this? Was wondering if anybody has a transmission wiring diagram they could send me? Thanx