wiring mysteries
 

I have a 1990 d250 auto. I pulled the dash to find out why my buzzer wasn't working and noticed that behind were the cargo light button Is, there is a wire marked o/d and it's taped up. There is also another of pluges that are not connected to anything and are just hanging under the dash near the pedals. One looks just like a tach plugen on my dad's 93. I'm just curious if someone swapped a harness of if there all like that. I don't think anyone swapped it since the truck only has 96 thousand miles and I'm the second one but I don't know. Thanks

There should be no O/D switch on a '90 as it has the 3 speed NON O/D 727 in it.

How do you know it only has 96,000 miles on it? Those years have the ODO that turns over at 100,000...it might have 196,000 or 296,000 on it.

I can't answer your question specifically but it is very common for wire harnesses to have unused connectors.

only the 89 had the odometer that went to 99k then back to zero. I don't know about all 90's but all I've seen have had the later model cluster that goes to 100 and has the 6 didgit odometer . That's what I was curious about though because it has the 727 so it shouldn't have a o/d switch (there is no actual switch .it's the female connecter for a switch to plug into its just labeled o/d) all I can think of is it somehow got a later wiring harness from factory? Kinda doubt it though. Or someone switched it and just did a very good job .I am going to snap a photo of it today so you can see what in talking about.

One size fits all. Not uncommon at all for manufacturers to make one harness and not use what was not installed. Saves a lot of money doing it that way. Looking at my 91 FSM, I don't see much difference between the gas and diesel versions.Very easy to just leave a wire unconnected or change the connector. A good example is roof clearance lights. Even though you don't have them doesn't mean the wire connector is not behind the left kick panel.

https://cimg6.ibsrv.net/gimg/www.die...d99891d12a.jpg
https://cimg0.ibsrv.net/gimg/www.die...21e9739666.jpg
It really confuses me. Maybe it means something else.

that would definitely make sense. I just thought they changed the harness when they added the over drive trans. Wish I got lucky and had the 518 though lol

The gas trucks would have had the O/D then. They probably use the same harness.

Never saw a factory harness with any labels except part numbers, someone has been in there.

It looks factory to me. Those things tend to deteriorate over time or get ripped off during repairs.

Anyone know what this is? It's behind the glove box. Thanks you guys I really appreciate the comments

If you meant to post a picture it failed to show up.

My truck has the Rear Wheel Anti Lock (RWAL) module behind the glovebox. Along with the heater box.

Edwin

[QUOTE=Angry Johnny;3353531]It looks factory to me. Those things tend to deteriorate over time or get ripped off during repairs.I have pulled apart many Dodge 1st gens, that is definitely not factory, looks like a Painless wiring or other replacement harness.



https://cimg9.ibsrv.net/gimg/www.die...e8019f68b8.jpg
Here is the pic. It didn't send before

I took a quick look but I didn't see a plug like that. Here's my RWAL plug and module FYI:

https://cimg8.ibsrv.net/gimg/www.die...6dc9a3e4a2.jpg
https://cimg2.ibsrv.net/gimg/www.die...366732ba44.jpg