Getting lost in the sauce trying to detox factory wires

[Surf44]

I would think I’m pretty savvy with electrical, build camper vans for a living, years of construction electrical, and have done quite a few normal vehicle stereo systems and wiring. But I am getting really stumped on trying to detox some of the wiring on my 2002 Thomas Freightliner. I've searched everywhere and watched the videos doing my due diligence to not just cut stuff without knowing where it goes. The wiring on this is insane, there are multiple wires just cut, connectors not being used and stuff tied together that in my head shouldn't need to be tied together also relays just every where dangling and the amount of extra wire and butt connectors that seem completely unnecessary is crazy!

A list of what I've already deleted

-The A/C took the entire wiring off that, still have the switches since for some reason they have jumpers to other switches.
-The radio, this one was the easiest straight forward was fused took it all out no problem.
-Stop sign and wiring pretty straight forward as well.

Trying to at least just delete the thomas Light Monitor and the flashers and delete the interlock system. But I would really like to clean up a lot of it because for one it just looks like a nightmare if I ever did have to diagnose something in there and for safety, I don't like wires dangling and sitting there live if they're not being used.

I am in Boise, ID if anyone knows some electrical/skoolie pros out this way would love to get some serious help.

Here's a video showing everything.

 

[Surf44]

Here’s some more detailed pics, that first is a relay that from what tracing I can tell seems to be for the emergency door lock in the back. But seems odd place to have that.


This circuit board for the light monitor when unplugged stops all blinkers brake lights and any other light it’s monitoring from working


This bulb in the middle of the switch panel was new for me, after some research it’s a signal stat flasher module. Still unsure why theres a bulb on the front side. The last pic is the backside of that switch panel

 

[ewo1]

First things first, contact a Thomas bus dealer, not a freightliner dealer, and get yourself a wiring diagram for your bus.

You got a mess!!!

 

[nikitis]

On my Thomas, I had the harness installed for a light monitor but the wires only go to open ended wires cut. The harness just tied into the existing light wires. Nothing else so when a brake light is hit, it just sends the same voltage to the light monitor. It shouldn’t prevent brake lights from working unless yours is wired first to the monitor and then from the monitor out to the outer lights. Then unplugging the monitor would break it. You could see if there were two wires per light on the monitor and if so is likely the case

 

[Surf44]

An update for anyone else that may come across this issue.

I ended up taking the wires that were coming from the main harness that were going to the light monitor and testing them with a volt meter to determine which ones were brakes, reverse, turns, and tails.

The interlock or whatever it is was just a relay that was splitting 2 pink wires butt connected those together and was able to delete all the wiring back.

Here’s the pile that was deleted!

 

[nikitis]

I'm curious, was the relay after the light monitor or before it?

 

[Surf44]

The relay wasn’t part of the light monitor at all. The connector coming from the main harness under the steering column that supplied the turns, brakes, ect. Went to the light monitor then the light monitor went to the lights. That connector has 2 pink wires that went to the relay then the yellow wire went straight to the back emergency door. They were just using the yellow as the switch to connect or disconnect those 2 pink wires.

 

[nikitis]

ah okay so it was as I originally suspected. It goes to the light monitor then from the light monitor to the actual lights.

This is different from my bus but mine is older than yours. My wires T off from the Flasher device, one goes to a harness which should connect to a light monitor (which was never installed, only the harness). One wire goes to the lights themselves direct from the yellow flasher device, and a second wire from the yellow flasher device on the same terminal goes to a light monitor.

I believe both ways use the same amount of wire, but T off in different places.

Thanks for the information, I'll bank it and use it to help someone else down the road who has your issue and bus.

 

[Surf44]

I do have another question, I’m planning on just deleting all the old wiring going to the back and wiring with new so it’s just dead simple trailer wire going to the back with new led lights and for the marker lights.

I was thinking I would go from the harness which is 16awg into a relay to then go back to each circuit. The 16awg would be enough since I’m going to leds but not sure if the wires off the harness are meant to be the source of power or just the trigger wire.

 

[ewo1]

Why redesign the wiring???
Makes no sense... unless of course the wires are physically damaged...
From an emotional view point, yes it feels good to have new stuff but why fix what is not broken?

 

[Surf44]

Why redesign the wiring???
Makes no sense... unless of course the wires are physically damaged...
From an emotional view point, yes it feels good to have new stuff but why fix what is not broken?

Mainly just because I would have to extend the wires now to be able to wire them up without the light monitor. There’s also a connector in the middle of the strand of wires going to the back which I don’t like a failure point inside the middle of the bus like that. It’s also probably $30 worth of wire which yes for that amount having a simple run of new good jacketed wire seems worth it to me. I’m also deleting their fuse block and going with a blue sea one.

To be fair I do agree with you it’s not broken not completely necessary. I think if I didn’t completely take everything apart to begin with I would have just kept it but at this point I’m going to be making my own switch board and building out the driver side dash section that will house it.

 

[nikitis]

I went through all of my wiring and traced every single one so I could learn what they did. I was not as well versed but now I know what every wire does minus 5 of them and that's mainly cause they weren't connected to anything at all.

 

[nikitis]

Do you plan on keeping the Light Monitor? I was looking for one if you were gonna toss it. Could I buy it off of you cheap?

 

[Surf44]

Dang, I tossed it last week.