Clearance light relay?

[epretot]

I lost my clearance lights.

All 14 of them went dark. I bypassed a junction (unknown location) and the front 7 lit up. However, not sure why the back 7 won't.

Seems like there must be a relay.

I'm also certain the electrical panel schematic is inaccurate. Perhaps some of the other 102Dl3 owners can send me a pic of the electrical panel door. Perhaps it will match mine.

I have the electrical schematics for the bus. And if they are accurate, then I'm stumped.

[buswarrior]

Is it wired stock, or been changed by a previous owner?

With which switches did they come on, before they stopped working?

Some fleets decide they want all the lights on together, and swap wires in the junction box to accomplish this.

Really screws up trouble shooting later on, if you don't know what was done.

Since you got them to illuminate via a jumper, you have a lead as to where they are connected.

Confirm if the headlight and clearance light switches are not tied together.

Let us know what your methodology has been.

Happy coaching!
Buswarrior

[chessie4905]

go to harbor freight and get a circuit tracer. Hook one to dead circuit and trace all wires till you hear signal. Power to be off. Works nice and not costly.

[epretot]

I'm nearly certain it's stock. It has had two owners. One coach company and a private school. The school made no modifications. However, there are some items disconnected here and there.

The lights previously came on with the headlights. The marker lights (lower lights) do still come on with the headlights.

I'm almost 100 percent certain they worked after demo. I will run the bus a few times a month and have noted the lights work.

The schematic shows power running to the back which also includes the license plate light. That's working so...

I'm thinking the problem is a junction point buried somewhere in the bowels near the dash. That harness is in frame and or dashboard. Should be fun. I could cut it loose I suppose.

This isn't really emergent as the bus is in the rough in electric, plumbing, hvac stage. But thought I would ask.

Good news is, I have an electrician who helps for food.

[richard5933]

Do you have a wiring diagram for your bus?

[epretot]

Do you have a wiring diagram for your bus?

Yes. It is was on metal panels in the cargo bay.

[RJ]

The lights previously came on with the headlights. The marker lights (lower lights) do still come on with the headlights.

The schematic shows power running to the back which also includes the license plate light. That's working so...

Toterpe -

From what you're saying, all of the running lights below the floor are working?

And all of the running lights above the floor are not?

If that's the case, IMHO it's time to start tracking down the wiring between the roof and the floor.  Unless it's a multiplex system, then that's way beyond my pay grade.

FWIW & HTH. . .

RJ

[epretot]

@ RJ

That's exactly right. There has to be a junction point I'm missing.

It's also possible that it is my own error. I cut back quite a bit removing bulkheads and lighting.

So, before I dig too much I'm going to cut back the heat shrink and study  that.

I left enough to see the ID in case something like this happened.

[epretot]

This ended up being a simple fix. I misread the schematics during demo and removed a wire from a stud in the rear electrical panel. That "fixed" the rear.

The front was a cut wire from the bulk heads demo.

I studied the schematics and was able to determine the mistake.

I have never read a schematic before. Amazing how much you learn when you have to. Makes a lot more sense now.

On to complex dash switches...

[chessie4905]

I had my electrical schematics enlarged 4 times, including the fold out, and airline schematics. Wow, what an improvement, and magnifying glass not needed.

[epretot]

I had my electrical schematics enlarged 4 times

I have the large metal panels from the bay. I used a scan of them printed on 8x11.

Dumb...

[buswarrior]

Use one of your schematic copies to record the replacements, and date them.

You will not remember...

As time goes by, you have more and more replaced, and then you start replacing your own work, and without doubt, get to curse or praise whether your installl methods were "next guy" friendly, or not...

Eventually, we become the previous owner...

Happy coaching!
Buswarrior