How to adjust the TV cable on a 95 dodge 1 ton - Dodge Cummins Diesel Forum
This is has some pretty good links and pics on the tv cable. Dont know if Ill get in trouble for posting up something from cf on here.

 

My TV cable has been adjusted ad nauseum. Any tighter and I don't get a 2-3 shift at WOT. Adjusting the TV never changes the 3-4 shift either, just 1-2 and 2-3.

 

I had the same issue with od shifting at 30-35mph under light throttle. As you did I adjusted the tps as much as possible but without success. I installed a potentiometer in place of the tps and wired in a voltage meter. I can adjust the shift into od from 30mph to 50mph or more with lockup coming in between 2 and 5mph after od. I typically leave mine at 1.9 volts which shifts at roughly 39mph at low throttle with lockup in at 45. Increased throttle still results in later shifts due to the later 2 to 3 shift. I increase to 2.6v with od off which results in a nice seamless shift in and out of lockup. The digital volt meter allows me to put it right where I need to without guessing. After having several cheapo pots go bad every other year I purchased a better one from McMaster Carr (item #7436K342) and so far it has held up well.

 

i'm having the same promblem,dealer or trans shop can't figure it out,did you ever get your truck fixed ? if so how?