OD wasn't working when I got the truck, that was fixed with new fluid / filter. Still have no lock-up.

This is my first Dodge (1990 Dakota Sport 4X4, 3.9 V-6) and the repair manual I bought doen't offer much insight into the transmission.

I've looked for the tranny numbers but can't get to / see them (0612 is cast into the bellhousing).

Where is the lock-up soleinoid located? Is thier anything else I should check first?

Thanks in advance!
Skynyrdcat