I've been doing some work on the 1990 Dodge D250 today... replacing the stereo with refurb factory unit, and prepping to install backup camera monitor...
I removed the dash face surrounding the instrument cluster and stereo to do the work and I noticed a couple of dead-end wiring harnesses I could not identify. My best guess is that Dodge used One Harness to wire all trucks, and since mine is a base model, there is no need for electric windows/mirrors/locks. The switch in the second picture really has me scratching my head! Anybody have a clue what these are? Thanks in advance!

This one is behind the glovebox and has no apparent place to connect.

This one was floating there behind the heater controls, not mounted to anything. Has a switch and looks like it should hold a big fuse or something.

 

the 1st probably plugs into an ABS box thats gone. The 2nd one is your dash/dome light for above the heater controls.

 

The second one looks like it was installed(see the indents from the screws in the plastic).

 

I'm guessing ABS is an anti-lock braking system, not airbags, right? I wonder why the PO would have deleted the male end of the harness... The dome light switch does look like it has been screwed into something once upon a time... Where would that normally be installed? I don't see an obvious location for it. Also, does a bulb go in that empty space? I've been dealing with parasitic battery draw down... since these both seem disconnected, I was thinking they couldn't be the problem, or is there a possibility one or both are contributing to the problem? Thanks for your response. Hopefully I can set things right before putting the dash back together!

 

Yes, I see signs that a screw was once in there. Any idea where it's supposed to live and what sort of bulb would go in it? Thanks for responding!

 

A search of the Ol' Youtube confirms that, yes, the switch is a map light! A channel called Decent Garage has a video up that shows it's proper mounting position and upon inspection, I discovered mine has been broken off. I think I'm going to do the right thing and use some stick on velcro to solve the mounting issue. Thanks again for the helpful responses y'all!

 

that connector in picture 1 is not abs. you can clearly see the abs module is still plugged in in the background of that picture. i would guess that is for the maintenance reminder module.

 

Thanks for the response... would the maintenance reminder module have a male connection I should be looking for?

 

most likely but personally i wouldn't waste time looking for it. there is a good chance someone may have even removed it from the vehicle.