Forum Discussion

IndependentMach's avatar
May 15, 2013

Electrical / Battery Issue

I've got a small machine shop in Oakland and we get all sorts of walk-up questions. The other day a woman who was a bit down on her luck came in the asking if we could help her with an electrical problem. She has a 1975 Winnebago (sorry, I don't know what model) and says she has the following problem:

Even with the engine and key off, things that should not be powered (like the windshield wipers) still work. The windshield wipers were the only example I can remember her saying. I know that lights, for example, can be turned on whether the car is on or not, as can the horn, but turn signals and the wipers should not.

Whatever the problem is, it's putting more of a draw on the battery, which isn't lasting as long as it should.

Unfortunately I don't have an RV and know nothing about the peculiarities of their electrical systems. I have no idea where I would start troubleshooting this.

Does anyone have any suggestions as to what part might go bad to cause such a problem? Besides the basic battery and fuses I assume there's something that runs inside lights with the power off (again, this is a 1975 model).

My plan was to do some internet research on whatever might be causeing this and at least print out some forum posts that might guide her through some troubleshooting.

Thanks in advance for any suggestions!
Conn

8 Replies

  • Excellent, thanks a lot for the suggestions, that definitely gives me some starting points to research.

    Thanks for the help,
    Conn
  • As suggested, if it was this way from the factory she may have sick batteries. I would check the batteries and then of course the actual draw on each battery. Could be as simple as that.
  • I"ve seen that SORT of problem before and it turned out to be a fuse that was blown and "back feeding" the electric system through another fuse. Happened in a Dodge but it certainly COULD happen in most any brand vehicle. In the case I had it was causing the interior lights to flash whenever the turn signals were used and a few other weird issues like that.
  • Is the battery electrolyte low? It may be just that the battery is weak.

    Jim
  • I had a 1972 Winnie which was wired in the same way that your customer describes. Things that were operated from the dash like the windshield wipers, washer fluid pump, lights, horn, turn signals etc. were always powered and could be turned on without the key in the ignition. I always wondered about that. But that shouldn't drain the battery. If those things are all off and the battery is still draining then there is some other parasitic drain that needs to be tracked down. You could take a multimeter and start checking circuits, the electrical systems on those Winnie's aren't that complicated. The easy way to take care of it would be to install a battery cut-off on the chassis battery.

    By the way, welcome to the forums. It's nice of you to help the woman out. Good luck with the repairs.

    Miles
  • A motor home has several separate electrical systems. Sticking to the dc systems there are two. The chassis system consists of the starting battery, etc.

    The house system also has a battery and charger.

    Normally they are separate systems but there is usually a switch that ties the two together for emergency starting. The two systems are probably tied together which causes things on the chassis side to have power.

    Others can probably explain in more detail but that is my guess.
  • One likely possibility is a worn ignition switch. If the front of it looks like a van vs a bus, then the systems you are talking about will be the same as a 1975 van of that make and model. It is pretty normal for horn and headlights to work without the key in, on a 1975.

    Jim