I recently swapped a TH400 into my 85 CJ, ditching the T-5. I notice that the reverse light adapter is different for the two transmissions. I'm wondering if it would be as easy as cutting off the T-5 end and splicing on the TH400 end. Or, finding the wiring and hooking it into my new B&M Star Shifter. PLEASE ADVISE!  

the plugin on the 400 is the electronic kick down.
the reverse switch on the factory auto is at the base of the steering column. you'll need to use the b and m.  

Ok. Where do I actually pull wire from to send to the shifter? Also, do I need to hook that electronic kick down back up? Not even sure what that means. Thanks for your help  

yeah, extend the wire to reach a new switch, which ya can get for the b and m shifter or just use a manual toggle switch.

the kick should get hooked up, it'll take a pedal or carb mounted switch, the tranny will live longer when electronicly kicked down vs. manually shifted down for passing gear or plain ol' giddy up.

I've got a pic of the kick down switch i'll dig up later, It's dark and I'm drivin right now..  

this is the kickdown switch on mine..

 

The shifter has a mechanism built into it that completes
the circuit when the shifter is placed in reverse. I am just wondering where I actually find the root of the reverse light wire. If there is one thing I dont know anything about, it is wiring. I've got some spare time tomorrow so I am gonna see what I can come up with. Thanks for your help!!  

use the plugin from the manual, extend the wireing to the switch.  

Ok. I guess that makes sense. The plug left behind after
the removal of the 5-spd must have had something to do
with the reverse light. my friend got underneat it and tested it to see if the reverse lights came on. they didnt but then i thought maybe they didnt cuz we didnt have the ignition on. thanks for your help