so i saw the tech article on jumpering the computer terminals to force lockup the tcc in 2nd-OD and thought i would try it on another car of mine.

the car has a th-350 transmission, and when i started driving i noticed that 2nd did not force a lockup, but 3rd did.

i was just curious if i should try a different jumper configuration or if this was how the th350 is no matter what.

(yeah, i know, 350 trannys are LAME, but hey, dont hate. actually, i'd like to put an underdrive (like 1.75-2:1) unit on back and put a 2.53 rear end in. i already have a 2.93 rear and turn 2100 or so on the highway at 65. a 2.53 would be just about perfect)

 

The 200 & 700 trannies have a hydraulic circuit that keeps the TCC from locking up in 1st even if the solenoid commands it to do so or is sticking.
I don't know much about the 350 but I guess it could have a couple of pressure switches in series with the solenoid to keep it from locking up in low gears that way.
If that's the way it works then I don't think there's anything you can do about it apart from doing some rewiring internally in the tranny.
There's certainly nothing else to try using the diagnostic connector.