I'm still trying to make the final connections to get the OD relay / Overdrive working on my manual to auto conversion. I'm a little stumped and need some input from the group.

I have the factory electrics manual in pdf form. If I am reading the schematic right the OD relay interacts with OD off solenoid (on tranny), OD on-off switch water temp switch, column switch, and panel indicator light.

The need for OD solenoid and OD on-off switch are no-brainers, and I assume the column switch is for a +12 volt supply. The indicator light is nice, but does not seem to be vital for OD operations.

BUT... the water temp switch has me confused. As I recall there are three of them and I have no clue which one to use, or what the purpose of a water temp connection is.

I really wonder if I could just wire the OD on-off switch direct to the OD solenoid without having major problems.

Is there a smarter guy that me out there that can offer some suggestions? Anybody have any ideas?

(As you can see I am NOBODY's Auto tranny guru.)

The water temperature switch is the beginning of the chain for the OD operation. There are numerous posts to this effect, especially folks asking about why they've lost OD on the otherwise 'fine' running Monty.

I have no idea why this is, but it's worth your research.

Thanks for the tip Rxinhed. I searched the OD problem and found a few items that may help.

Still kinda scratchin my head as to why the connection between temp and OD as it appears as though it is NOT an overheat prevention switch, but one that keeps the OD off when the engine is cool.

Maybe it is an emissions thing...

Thats why its there smog ....Grounding it will bypass it...

Yup. On the 2.6, that switch turns off o/d on overheat. On the v6, it disalbles o/d during warmup. In either case, it's pretty safe to ground that wire. That wire grounds the whole o/d solenoid enable circuit.

I happen to know that on a 2.6, the truck will not shift into OD until the temp reaches normal range, so it works that way, too.

John B.