DIY CDL extension harness and backlight feeder

[wearsabrowncoat]

This is a DIY project to extend your CDL harness and make backlight feeder wires for additional switches such as fog lights, inverter, and heated seats. My main objective was feeding backlights and the CDL connector was the best choice for the project because it has the CDL connector cap which provides the requisite female end of the extension harness. I don't know if any of the other connectors can be matched with a female end. Usually they just plug into the back of a switch.

By the way, this is my second time doing this but first time documenting the process.

The key parts are the original CDL connector and cap. I don't know if this is a part that can be ordered but I acquired mine from the junk yard:


To make an easy project, pull the complete subharness that the CDL is attached to:


This is a picture of the sub-harness connector that can be found back near the ashtray, once you unplug this and all the switches you can pull the harness out as pictured above:

 

[wearsabrowncoat]

Strip all the tape and covers off the harness:


Trace the wires from the CDL connector to all the other connectors and carefully remove them. To do this, pop the locking plug up with a small flat head electrical screwdriver:


Then using the same screwdriver pry up on the small plastic tab while pulling the wire from the bottom:

 

[wearsabrowncoat]

One of the connectors is slightly different. You need to pull up on the plastic looking piece on the face of the connector before prying the plastic tab holding the wire:


Now you should have your CDL and a bunch of loose wires connected to it:


For reference you can see that the CDL is a 10 count connector but only 5 slots are used:

 

[wearsabrowncoat]

OK, slight problem here. It looks like all the wires in this CDL are female to female like this:


To make this work I need male to female wires like this:


I don't remember running into this problem the first time I performed this procedure but it was over a year ago so it is possible. I think the difference here is that the first harness came out of a 95 and this harness came out of a 93. This wasn't that big of a problem for me because I pulled some female to male wires out of this connector I had in my scratch bin:


However if you are following along make sure you get some male prongs in your bundle of wires from the junk yard or contact Cdan for some so you can solder them on. Keep in mind that the CDL cap has the yellow jumper wire that has two male prongs so if you use those you only need three more.

 

[wearsabrowncoat]

You will notice that three of the wires coming out of the CDL connector have multiple wires spliced off of them. There is a yellow, a green with white stripe, and a white with green stripe.


I pulled the yellow wires but you will want to retain the green with white stripe and white with green stripe wires if you plan on adding aux switches later that require backlights as that is what these powered for. In this bundle there are 5 sets of additional backlighting power if needed. That is after one of the female ends was replaced with a male end.

At this point you need to run wires from the male CDL connector to the female CDL connector. To do that you need wires with male and female ends. As previously discussed, I pulled three of these wires from my scratch pile and I added male pins to the backlight powered wires. The easiest way for me was to replace one wire at a time.

So now the extension harness should look like this:

 

[outinthewoods]

more please!

 

[wearsabrowncoat]

Before using this extension, cover the exposed leads on the backlight wires with tape or heat shrink. Not doing so we cause shorts, burnt fusses and possible crapped out backlight rheostat. Heat shrink pictured:


Also, you might want to add some zip ties to clean the bundle up especially if you aren't immediately using the extra backlight wires:


For me this project was initiated so I wouldn't have to cut into the factory harness to get backlights for my aux switches (fog lights, driving lights, interior winch control, sub fuel pump, CB holder, heated seats, and inverter to name a few). The extra length in the wiring loom was a bonus when repositioning the CDL to the bottom row of center switches.

That's it! Let me know if you have any questions.

 

[wearsabrowncoat]

I just thought of another detail.

I don't know how many extra backlights you can jump off your extension if using the stock bulbs. I am running at least 7 extra backlit switches but I put in LEDs as listed in post #4 of this thread: https://forum.ih8mud.com/80-series-tech/213060-definitive-led-thread-80s.html