(Formally "Plan V: A Van Dwelling Blog", when I lived in a 1978 Dodge Xplorer 228 Class B motorhome van)

Saturday, November 3, 2012

Rewiring running lights, part 2 - More problems.. elsewhere!

Man... just when I thought I was done with major electrical work.

I went and got 5 gallons of gas today and put it in the van and got it cranked up. (Which reminds me, I need to check my new hose connections for leaks now that fuel is in the lines.)

Low and behold... I stick it in reverse to make sure the backup lights are working.. and they weren't. And what's this?! The blinkers stopped working! ..Flashers work, but not blinkers. I look at the fuse panel and find #2 fuse is blown. (#6 was blowing for the running lights).

So after hours and hours of screwing around trying to get it to stop blowing fuses with no luck.. I figured out that it seems to only blow the fuse if left in reverse for more than a few seconds. In park, neutral, drive... it can be left in them and the fuse doesn't blow. If you hurry past reverse (in either direction), the fuse doesn't blow. But as soon as you leave it there... it blows the fuse.

An oddity about the van is that the horn only works when the engine is running which is NOT normal. The little bit of paper work I got with the van shows it failed a TX state inspection for a non-working horn. It's not really a big deal that the horn doesn't work when the engine is off.. but I may venture into fixing that as well since it's just a matter of routing the wire to a constant connection instead of a switched connection.

This may be a clue to why the fuse blows only in reverse since the horn is on the same circuit as the turn signals and presumably the backup lights as well.

I'm looking into if the backup lights are supposed to be wired directly to the neutral safety switch, which is what it appears to show in the Haynes manual schematic. If they are, it's a matter of running one new wire from the harness to the backup lights... like how I did to restore the running lights to working condition on the factory headlight switch.

In the meantime.. I bought some auto-reset circuit breakers that can used in place of glass fuses/ I ordered 3 sizes/2 kinds: Bussmann 10A & 15A & Dorman 20A. The Bussmann ones may not fit into the Dodge fuse panel.. but I may have a use for them in the motorhome's "house" fuse panel. The Dorman one will fit for sure but i wanted to try a smaller amperage rating one if possible so it and the wires don't heat up as much before the breaker trips. The factory fuse for #2 is 20A so the Dorman should be safe to use if the Bussmann ones don't fit.

This will allow me to go into reverse as needed and let the circuit breaker trip as needed instead of blowing a fuse. If I have to replace a fuse every time the van is put into reverse... that can get costly fast!. Never mind the fact that I'd also have to remember to stop and change thee fuse before I even drive forward any since the blinkers and horn would no longer work with due to the blown fuse. At least with an auto reset circuit breaker... it will resume working after it cools down again. It's by no means a proper fix.. but it will get me by without burning up the wiring or replacing endless fuses.

If using the factory wire harness with a new piece of wire to the backup lights doesn't work, I guess I will wire a special switch for turning on backup lights and the backup alarm. The alarm will at least remind me to turn it back off again but that's also annoying and borderline unsafe.

Sorry, no pictures today. Nothing worth seeing anyway.


  1. One trick I use to avoid wasting fuses while working on problems like this is to buy a dual element tail light. The kind where the wires coming out of the bulb are about 1/2" long. Twist the two wires on each side together so the elements are in parallel, then crimp them into 1/4" spade lugs that fit into the fuse sockets. The bulb will burn brightly when the short shows up. Makes it much easier to trace a short. If there's no short, the bulb will burn dimly and so will any bulbs downstream.

  2. Well, it seems I fixed the problems by running new wires. No more fuses blowing. I kept the auto-reset breakers just in case but I never even opened the packages.