Working on cleaning up underneath my truck to isolate the auto trans fluid leak, and I discover that I am missing a section of the wiring harness. Specifically it looks like there is a small electrical plug on the driver's side of the transmission. It's on the side of the transmission case just above the pan. I'm not looking at it right now, but IIRC, it looks like three pins, so I'm assuming I should have a wiring harness somewhere to plug into this. Nope, nada, not there, There is one wire that has been snipped coming out of a harness running down the driver's side frame, but it's too dirty to determine color.

So, I'm assuming this connection is for the reverse lights, right? Anything else I;m missing out on by not having this?

Anyone got a parts truck they'd snip this connection and a few feet of wire off for me??

 

Wiring harnesses are built for all possible accessories and options for that truck that year. You will find dead end wiring with connectors all over the truck if you look. What trans do you have?

 

A904 transmission, or I think so. I need to clean it up and be able to read the ID number to be sure.

Here's a pic I found online of what the connection looks like. Identified on a parts website as the neutral safety switch.


Snipped from a website I found:

The neutral start switch performs a couple of functions. It allows the engine to be started when the transmission is in only park or neutral range and it controls the electrical current to the reverse lights when the transmission is in reverse gear (This type of neutral switch has been used since 1969. 1968 and earlier cars had the reverse lights controlled from a switch on the steering column or console shifter).
The wire coming from the frame mounted wiring bundle was rather crudely snipped and left uncovered, so I'm sure I owe that to a previous owner, not the factory.

 

I totally misunderstood your first post. When you said; "it looks like there is a small electrical plug on the driver's side of the transmission." I thought of an electrical plug to be on the end of the wire instead of the socket on the switch.

If you take your truck off road a stick can get caught on the wire and tear it out at the harness. Maybe that is what happened. I know I have lost wiring like that.

I am surprised the truck starts. There is some wiring jumped somewhere because the center terminal of that switch grounds the starter solenoid circuit. Without that ground the truck can't start. If you hook it up you will have to find and remove that jumper to make it start only in Park and Neutral.

I don't have a donor, sorry. That part is not a high use item though so I would think it would still be in most trucks in a junk yard.

 

Yeah, I thought it was odd that it would start, and I'll have to backtrack the wires to see where someone jumped the circuit to bypass the NSS. The idea of losing to to a road hazard like a stick or tire-gator makes sense when you consider I'm also missing a speedometer cable. They would have been very near each other going into the same side of the transmission.

As for finding one in a boneyard, I only know of one D-series truck in a boneyard nearby, so I'll give that one a shot. Wonder if Dodge vans from the same era would have the same wiring pigtail? There are a couple of mid/late 70's Dodge vans there.

By the way, at lunch today I zipped home for something, and while there, gave the ole truck a test. Placed the transmission in D, and turned the key. Yep, starter turned over!!! BYpass confirmed. Gotta fix that.

 

the vans have the exact same plug on the transmission. your truck will run whether or not it is hooked up. the only difference is if you don't have it hooked you can start your truck while in gear and you don't have working backup lights.

 

Yep, I have verified that I can start my truck in any gear, and that I have no reverse lights, Hoping to have a productive trip to the boneyard soon. I also continue my search for a rear bumper for my stepside. An original stepside Dodge bumper I ave given up on, now I'm looking for something from another model truck that comes close, and I'll just have to fabricate brackets.

I love my ole Dodge truck, but I sure wish we had the aftermarket support Ford and Chevy owners enjoy.