After chasing electrical things in most everything that moves, for over 40 years. I agree with Johnny, check every connection. A key point to remember, and remind ourselves regularly, every circuit consists of a feed wire, the load, and the return wire.
In 12V circuits, the positive lead is the feed, the return wire is the ground wire, that is typically connected to the nearest piece of bare metal, and basically, you are hoping for the best. Do not hope for the best, run a new black wire back to a negative buss bar immediately next to the battery terminal, no splices, no shared load. It is painful, it is hard to do, but it is the only way to guarantee clean electricity to that load.
In my experience, the most likely cause of electrical woes is user modified wiring. Undersize wire, no fuses, improper crimping tools, improper lugs.. How many of us have replaced the dash mounted radio and just spliced in the power wire turned it on and said good enough.
Did you note how much additional power is needed?
Did you increase the size of the ground wire to handle the additional load?
As far as the common wiring techniques used in the coaches. A tin plated copper lug, mechanically attached to an aluminum bar, with a cadmium plated self drilling steel screw. Add 40 years of contact. Does anyone miss the point that you are dealing with a mechanically built battery that is corroding itself apart?
To properly deal with this system, you must disconnect the connection point. Inspect the lug for loss of the tin, corrosion of the aluminum, clean both with a piece of Scothbrite, not steel wool, and put back together.
My experience tells me that the wire that is most likely to be the heat up and fail culprit are the ground or return wires.
Considering the AC wiring in the coaches, DO tighten up the connections in the main circuit breaker box as part of your start of season ritual. Do it with the coach unplugged only. Do not work on energized circuits.
As far as the AC outlets in the coach, do NOT use the push in the back wiring points in the outlets, they will melt if you use, even occasionally, heavy AC loads, like space heaters, microwave ovens, etc. Use the screw connections always. Spend the $1.50 more and use the commercial grade outlets.
Be SURE that the main panel does NOT have the neutral on the ground connected together in the coach subpanel. Bad things can happen!
Follow the original schematic as done by GMC. The people who built our coaches were professionals in their various fields, trust them.
>
>
> Bruce, what you say is mostly true.
> However you do not have to be a certified electrician to check and tighten screws in electrical boxes. You said you did yours several years ago. Are you a certified Electrian? If it was several years ago you really should do it again.
>
> Any owner can easily check and tighten the screws in his motorhome breaker and receptacle boxes. Just be sure to unplug the coach before doing it.
>
> Another thing is that one shouldn’t wait several years to do it. I check mine every couple of years and often find screws that have loosened. Besides the softness of the copper wires the thermal heating and cooling of the screws cause them to loosen. I don’t think one needs a certificate to turn a screwdriver, anyone can do it.
> As far as having a Certified Electrian check all the motorhome at the GMCMI convention, who will pay for that? If he spent 45 minutes (that’s working very fast if he is also checking all the receptacles) on each motorhome that would be about 94 hours of time or about 16 hours per day for the 6 day convention. That would also be $9400 at $100 per hour if you could get a certified Electrian to work for that.
>
> I don’t think you could even get volunteers to do it as they would be paying over $400 to attend plus perhaps a few hundred in gasoline. They wouldn’t have time to do anything else at the convention.
>
> I believe that individual owners should do their own. Perhaps someone could do a one hour seminar on how to open an electrical box and identify the screws and how to turn a screwdriver clockwise.
>
> Emery Stora
> 77 Kingsley
> Frederick CO
>
> >
> > I won't be able to attend the Rally, but I would like to offer this suggestion....
> >
> > Have a certified Electrician check and tighten all 120V electrical connections in the coach. Copper is a soft metal which can deform over time under
> > the screw head connection. Also driving the coach shakes everything. Over 40+ years the connections in the breaker panel and at receptacles will have
> > loosened causing resistance or intermittent connections. Current through a resistance dissipates heat which leads to increased resistance and more
> > heat then thermal runaway and fire. Also have them replace any receptacles that have loose plug connections. Changing the receptacle at the kitchen
> > counter to a Ground Fault unit is also a very good idea for your safety.
> >
> > I did mine several years ago and at each connection I could tighten it at least 1/2 turn and two breaker connections were very loose.
> > --
> > Bruce Hislop
> > ON Canada
> > 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> >
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> > My Staff says I never listen to them, or something like that
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> >
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
