No O/D after trans fluid leak
 

Towing my trailer the other day, trans line leaked at quick connector, noticed it when lost overdrive. Repaired problem, topped up (4 litres), still no O/D. I'm sure it got quite hot, would excessive heat cause band adjustment issue? Anything else not like getting too hot? With O/D button off, seems to shift fine. Cleaning up mess this morning found round 3 pin connector on left rear of trans was hanging off. Thought it was my lucky day, but replacement/road test showed no improvement. Any ideas?
Thanks,
Seann
1996 2500 4x4 12v/auto