tranny swap complete, help with lights

i am working on a 90 b2200 that has been swapped from auto to manual transmission
everything has swapped out, mounted, and been driving it for awhile now...
one thing not working is the reverse lights, i got to looking and my small amount of investigating has turned up it seems that the "reverse light switch" must have been on the shifter assembly on auto, and now seems to be towards tail of manual trans, i gather this from the lack of wires by tail end of trans, and the fact there are 3 plugs hanging out coming from under driver seat.
unfortunate part of this is i wasnt around when the auto was pulled out, so i really dont know what these go to
can anyone tell me if i am right so far on one of these 3 plugs being the "reverse light switch" plug?
maybe someone who has done swap can tell me which one it is, and maybe even which wire would go to which side of switch in tranny?
any help would be appreciated
thanks in advance

update:
i went out and tested a few things i could think of, i tried jumping over each plug(instead of going to sensor then back out, just used a wire to "complete circuit")
no lights, went thru and hooked up wires to sensor and tryed tapping into plugs...nothing

so either none of these 3 are right, or i somehow i dont have power to them...no fuses that i can find are burnt

i searched on here for this, and only thread i found was asking about the same thing and the guy and other members got into a big crap flinging contest and no answer was supplied...

The back up light switch is located on the transmission, should have wire going in B/Y (Black/yellow) powered by the ignition switch when "on" and runs through a 10-amp fuse labeled "meter". With ignition on, you should have power at this B/Y wire, confirm with a DC test light or DC voltmeter/multimeter.

The wire going out to the reverse lamps is R/W (red/white). With ignition on and when in reverse gear, you should have power in the R/W wire.

The stoplight sockets are grounded using a black wire.

im sitting in truck right now, the " meter" fuse is good, the switch on transmission has 2 wires..they were never connected to anything since i got truck..both are completely black from what i can tell
i am not finding any other wires anywhere under the truck that could remotely come to this location
the 3 plugs that come out from under carpet on driver side by shifter have wires as follows :
smaller 2 pin plug- pinkish color and a black with yellow strip
larger 2 pin plug-black wire, and a red w/green strip
smaller 4 pin plug-white w/green strip, black, black w/yellow strip, and blue w/red strip

obviously these dont match what your saying, so am i not looking in right spot or what?


do know the wire at the lights is red and black

I was looking at a 1991 Wiring manual, the only resource I have at work.

To test the back-up switch independently, set the multimeter in resistance (ohms) scale. There should be continuity between the two terminals only when the transmission is in the reverse position; otherwise, should be "open" or infinite resistance.

now for clarification, your talking about checking the sensor with no power or anything hooked to it correct?




still trying to figure out where ORIGINAL reverse light switch plug/wiring is on 90 b2200 so i can run it to 5 speed sensor

I sent PM

Been trying to trace a few wires and honestly not having much luck
Would be so much easier if everything was there and I was diagnosing why they don't work instead of not having anything hooked to transmission at all

Anyway, here are the 3 plugs I was talking about
None have power at anytime when key is turned on as of right now







Once again, if anyone knows that none of these are right, please let me know

Maybe someone with an automatic B2200 like Dan Woodland can check on his truck. PM him.

Looking at wiring diagram you sent me, it seriously looks like I am missing a part of wiring harness or something.
I will do that
Thanks