no overdrive help 89xj

i have an 89xj that i use mainly for mud and sand. i sometimes use it to drive around. my jeep doesnt want to shiift by itselff. i have already put in another tcu but still the same. i also put in another tps and adjusted it and checke the voltage. i hot wired the tcu and shift manually from 1 2 3 put once i turn of solonoids 1 and 2 i dont get 4th gear. i heard sombody saying that engine has to be at operating tem for it to be able to shift to overdrive is this true.
sol 1 ON Sol 2 OFF 1st gear
sol 1 On Sol 2 On 2nd gear
sol 1 off Sol 2 on 3rd gear
sol 1 off Sol 2 off 4th gear.

No its not true. It will shift into overdrive anytime.

Unplug the TCU entirely and shift manually (mechanically). Do you get 1 3 and 4?

This may help:

www.awshifting.com

Manually control your AW4

well thanx i disconnected the tcu and now my overdrive works. especially since i can control the shifts i get all gears 1 2 3 and 4 just what i wanted, thank you again.

ok, so you have an electrical problem.

Remove and clean your NSS.

Make sure your 'power/comfort' switch illuminates when you put it in power mode - if it doesn't, it can imply a problem with your brake light circuit.

Make sure your brake lights work.

Report back here.