Hello everyone. Found this site using Google while looking for a solution to my current problem.

Recently purchased a 1985 dodge truck and while trying to get it state inspected, learned that my backup lights don't work. Have pulled the bulbs (one was rusted in the socket) and used my handy-dandy circuit tester and discovered there is no power to the bulb socket. Traced the wires up the frame to the transmission (where I assume they plug into the neutral safety switch - 3 female receivers in the rubber boot) and am searching for power there.

The fuse (according to the user's handbook that came with the truck) says that the #5 fuse runs both the turn signals and the backup lights. Well, the turn signals work great... just not the backup lights.

Any suggestions? Any help is greatly appreciated!

The neutral switch, and back up are 2 different switches.
You could unplug at transmission, apply power to Reverse bulb socket, and look for voltage at transmission switch. See if you have power to other pin of plug for power with
Ignition on. You could jump at switch, or verify continuity at switch for problem.
Some of the older vehicles had problems with the ground on bulb socket.

The neutral switch, and back up are 2 different switches.
You could unplug at transmission, apply power to Reverse bulb socket, and look for voltage at transmission switch. See if you have power to other pin of plug for power with
ignition on. You could jump at switch, or verify continuity at switch for problem.
Some of the older vehicles had problems with the ground on bulb socket.

Stratmando: Thanks for the lead. Here's where I am now (because I don't have any Chilton's or Haynes book for this truck yet), I REALLY appreciate your assistance.

I realized power on one side of the boot that plugs into the tranny when I turned the key on. I used my battery charger and applied power in 'reverse' (at the backup light sockets) through the wires to the plug at the tranny. Viola! Had power now to 2 sides of the boot. Figured it was a bad switch. Auto Zone had one (didn't look exactly the same, but it screwed in OK), hooked the boot back up and... crap! No joy!

I tried to get them to come on with just the key on and the truck in reverse AND with the truck running and in reverse, nothing...

Any other leads?

Many thanks!

With power to switch, and from sockets, sounds like bad switch. Insert a jumper, or have someone watch backup lights, while with key on, you make connection and see if backup lights lite to verify. Clipping continuity tester with buzzer can be handy, just clip on switch terminals
Then, just place in reverse, with correct switch, and in reverse, it will beep.
If you back up to a wall. You could see lights working, while you jump underneath, also to verify.

The Ground is VERY important, run wire from Known hot for reference to see if you can get a bulb to light, If it doesn't light, it's a bad socket ground. This is no tools, What tools are you using?

With power to switch, and from sockets, sounds like bad switch. Insert a jumper, or have someone watch backup lights, while with key on, you make connection and see if backup lights lite to verify. clipping continuity tester with buzzer can be handy, just clip on switch terminals
then, just place in reverse, with correct switch, and in reverse, it will beep.
If you back up to a wall. you could see lights working, while you jump underneath, also to verify.

Hey again! I was successful at using a jumper wire from one of the outside terminals across to the other outside terminal on the boot and the backup lightbulb lit up just fine! I put in a new switch, hooked the boot up, put the truck in reverse (both with just the key on and with the truck running) and nothing.

It's a brand new switch... I'm confused.

It is bad switch or position it is in. Or a part broke in transmission. I think it is switch or position it is in.
Back up to wall leave key on truck in reverse, try to see what it takes to make the switch work.
Don't spend too much time, as key is on. You're doing good.

It is bad switch or position it is in. Or a part broke in transmission. I think it is switch or position it is in.
Back up to wall leave key on truck in reverse, try to see what it takes to make the switch work.
Don't spend too much time, as key is on. You're doing good.

Before I spend much more time beating my head on the tailgate here, I got to question... what is supposed to be inside the transmission behind the switch? Anything? Is something supposed to be in there that applies pressure to the back of the switch and direct power to the other outside connector of the boot and then back to the backup lights?

Reason I ask is because when I pulled out the old switch last night, I took a tranny fluid bath... is that to be expected?

BIG thanks yet again!

Is is a ball and plunger? Can you describe switch, mounting, and do you see how switch operates.
You may have wrong switch. How similar are they?
More likely switch than tranny.

Is is a ball and plunger? can you describe switch, mounting, and do you see how switch operates.
You may have wrong switch. How simular are they?
More likely switch than tranny.

The two switches are pretty similar, they differ only in that the new switch had a longer piece of plastic that went inside of the tranny.

To describe it:... both have the 3 male prongs on the outside that the boot plugs into. The part that goes into the tranny has a long piece of plastic with, what appears to be, a really small ball bearing right smack dab in the center of it. You can depress this piece of plastic, forcing it into the main part of the switch itself, which made me wonder whether there is something supposed to be in the tranny that would push down on the plunger.

My thought is that the plunger is pushed into the switch (somehow when I shift the truck into reverse), and that is what would direct power to the other outside wire, which in turn would provide power to the backup lights.

Thanks a million for your help and patience!

No problem, You should be able to turn key on, and push in plunger and see if the lites work. Maybe try the old switch, just plug in, push in.

You could have someone place vehicle in reverse, while you watch inside transmission with flashlight.
Have them turn key on(so you can place in gear), but not start. Disconnecting battery a little safer?

No problem, You should be able to turn key on, and push in plunger and see if the lites work. Maybe try the old switch, just plug in, push in.

You could have someone place vehicle in reverse, while you watch inside transmission with flashlight.
Have them turn key on(so you can place in gear), but not start. Disconnecting battery a little safer?

Stratmando... GOT IT!

A buddy of mine had a Chilton's that covered Dodge/Chrysler products. Stepped through those processes, still had the same problem! Pulled the new switch back out of the tranny and peeked inside to check on the actuating arm inside... indentation was lined up perfectly when the truck was in reverse (REALLY confused now). Took the old switch and the newly purchased one back to the auto store 'cause it appeared that the newer one went in the tranny just a little too far, thereby causing the little button to be pushed in and opening the circuit.

Long story short, discovered that a neutral safety/backup switch from a 1991 was the correct switch! (never wudda guessed).

So... thanks a MILLION for your help!

Hope to be able to return the favor to someone else out there.

Hey, you already did, someone else will have same problem, your info helps. Thanks for replying.
Take Care.