Ok well I have an 85 automatic whose O/D light stays illuminated on the dash regardless of button position on the side of the shifter. Car only operates in 3 fwd gears and reverse...no o/d obviously. There doesn't seem to be a lot of info out there on these jatco's...even the factory service manual doesn't devote much attention. Any idea where to start with this...I think there is a solenoid or a relay of some kind behind the pan in the tranny next to the valve body but have nothing to confirm.... Any help is appreciated as always guys.

 

This has an O/D off button right? Try disconnecting it and see what happens... Your switch may be stuck...

 

This auto is basically a 3 speed with a planetary OD case added between the tranny and torque converter. It is not uncommon for the OD section to fail before the rest of the tranny.

 

I haven't had a chance to do anything this week, but probably this weekend I will unplug the o/d switch and see if that makes a difference in its operation.