I don't recall seing the V6 in an 89, I will check. I do have the 90 and 92 wiring and will look there. On the 3spd auto to 5spd the only difference is the back-up lights and a ground wire for the starter relay instead of going to the neutral safety switch. On the A604, the whole system is really weird. I think I did put some V6 stuff on there. The 90 AG and AJ stuff has the 3.0L wiring. It is the whole wiring section from the manual. Look at page 17, it is the 5spd starter system (all engines).