Shifting problems (maybe?)

Ok, Im still working on that 90 wagoneer, 4.0, aw4 auto, np242, d30 and 35. Three inch lift, 31's. Seems like at highway speeds, the converter is not locking up like it should. I just assume it is supposed to lock up like every other overdrive Ive ever driven. Is this the transmission, the converter, or maybe just a sensor? Any and all opinions on this will be greatly appreciated, as I am at a loss for the moment. Thanks...

Do your reverse lights work when you are in reverse? When my NSS (neutral safety switch) was bad, my torque converter would not lock up. I cleaned the NSS and the problem was solved. I did not get an error code when my NSS went bad, some people get P0705 and P0700.

The lights come one, but I believe I have to wiggle the lever a bit to get them on. Thought maybe it was just age.

Few things to do:

Fluid--quantity and condition.
Throttle pressure cable adjustment.
TPS test and adjustment.
Comfort switch in the dash.

Post up if you have checked all those already and we can go from there.

Good luck.

Checked the fluid, and the throttle pressure cable. have not checked the TPS. What does the switch do? Wouldnt it lock up in either setting? It is on comfort right now.

It changes the shift points. Just wondering if its working and what position its set in.

Also, forgot to mention the brake switch, check its adjustment.