4103 exterior lights

[2xclutchin]

Hello all,
      I was wondering if anybody has a idea on how to even start with this project. Here it goes. Our 4103 has a little....okay rather important problem that only the front top right marker light and front middle clearance? light work. Once you flip the switch they stay on for a second then the breaker trips. I understand that this would mean there is a short in the 35 feet worth of 60 year old wiring, but where is the best place/way to start? Headlights, brake lights, and turn signals all work just the pesky marker lights. Oh and what a surprise all the bolts are seized on the light housings also. Thanks in advance,
                                 Mike

[Melbo]

Well the seized bolts is the place to start --- I don't have a good and consistent solution to that but pb blaster has helped sometimes.

Saving the lenses when removing the bolts would have to be first priority for me

Good luck I wish I had a "magic solution"

Melbo

[DMoedave]

For sure start at the lights up top. you might have to drill out a screw or two but these are notorius for letting water into the coach and causing mayhem. Not sure if your bus has a seperate switch for the clearance,sign,and running lights but ours does/did. alot of the wiring was accesable with the sign door but your sign is below the windshield (to stop LOTS of leaks) Any door or wiring openings above the dash at all?

[gus]

The wires passing through the body sheet metal to connect to the light socket are infamous for having the insulation cut through and shorting out.

Just as bad is the ground connection to the light or a connection to the bulb socket corroding so much it loses contact.

[2xclutchin]

I'm gonna have to get back to you guys on the dash stuff, if something isn't right in front of me I have a heck of a time. Probably find my moms camera and take a few pictures also, no guarantee on when I'll get the chance but hopefully soon. Thanks for the help so far.
Thanks,
          Mike

[zubzub]

I'm going to guess the '03 is set up pretty close to the '04 in which case the front  running lights junction in the driver's electrical panel and the  rear RL junction from the rear panel with a line from the front panel powering them.  This information will help you isolate whether it is the front or rear RL that are shorting (ie disconnect one set, power the circuit and see if the breaker trips).  From there it is hard going as the RL cowlings and screws are very hard to remove if a genius has used steel screws into the aluminum panels (on my'04)

[2xclutchin]

oh oh one more question!  Where does one find wiring diagrams?
Thanks in advance,
                         Mike

[buswarrior]

I would try isolating the wiring to determine the general area on the coach.

Why bust lights that still work?

Broken lenses are the conclusion to seized fasteners, unless you have the religion for penetrating oil use, patience of many hours over days, and use a jig for the drill.

For documentation, Dallas has a 4103, he lives over at BNO now.

happy coaching!
buswarrior

[qayqayt]

OMG the clearance light project was such a can of worms for me.  I have the wiring diagrams for my coach, so was lucky with the wiring fix but the rusted fasteners were an adventure and of course I broke one of the lenses when I tried to clean it and it disintegrated.  My advice... work carefully and slowly, get a rivnut tool ($40 - $50) to replace all the rusted out, busted rivnuts.  Use neverseize and brand new fasteners.  If you can't replace the light fixture gaskets, use strip caulk to keep the moisture out of the fixture.

Bryan

[gus]

Fortunately there is a nice standard plastic replacement single light available which were installed on my 4104 when I got it. It is Signal-Stat model 1350A. This is a chrome cab marker light for a Ford. I got mine at mike@truckpartseast.com for about $20 ea. It is probably available at auto parts stores.

It is not exactly original but close enough that any but the most picky won't know the difference.