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Gonzo42's avatar
Gonzo42
Explorer
Jun 17, 2019

12 VDC loss

No power in the cig lighter socket at the dinette table, no porch light, no stairwell light, and the aux battery switch no longer has loud switching noise.

Checked all circuit breakers and fuses twice, nothing found.


Any ideas?
  • Gonzo42 wrote:

    All these issued resulted from one of the two house batteries dieing (propable internal short), killing all the 12 volts in a about 30 minutes or less.


    IF.....you have 2 or more batteries in parallel and one of them developed a shorted cell, that could have resulted in very high current through the battery disconnect switch.....from the one that is still good. Or was still good. Likely both are shot now.
  • Aux battery switch in in the stepwell and has a small light next to it. Activating or deactivating always resulted in a solid thump.

    All fuses were checked visually with a flashlight first time around and them pulled and inspected second time around.

    All these issued resulted from one of the two house batteries dieing (propable internal short), killing all the 12 volts in a about 30 minutes or less.
  • Wiring Diagram from WInnebago Website http://www.winnebagoind.com/diagram/2008/08_524h_wire_160995.pdf

    and the master list available for all models https://winnebagoind.com/diagram/Wiring.htm
  • You NEED a multi-meter to check voltages.
    Without that, you need to find an RV shop to check it out.

    Dead battery.
    Loose battery connection.
    Failed "aux battery" solenoid (fairly common).

    But you should NOT be doing ANYTHING based only on a guess.
    Some testing is necessary.
  • Check your ground wires where they connect to the frame / chassis.

    I chased a similar issue with loss of power to certain circuits although everything checked out OK with fuses etc.

    My grounds were connected to the Ford Chassis Frame rail at a common point using ring terminals (approx 14 wires on 8 ring terminals) half were very corroded where the wire was crimped to the terminal. 1 was broken complete & this was the circuit I was chasing for the better part of a week.
  • Dead Aux Battery. Start engine. Make sure your on aux power via switch ON. Does porch light come on when switched on. If not then likely isolator has failed. It is supposed to direct the engine alternator juice to the engine battery and when the engine battery no longer needs charging it is supposed to send the alternator power to the Aux Battery. The isolater default position is charging the engine battery so when it fails the engine battery will always get the charge and never provide charging to the Aux Battery. Isolator is usually under the hood and is an add on by the motorhome manufacturer. Not a very expensive part. Total cost will be more in the labor to install.
  • Please explain what you are calling the Aux Battery Switch. Circuit breakers are 120 volts so forget about them. The only breaker that has anything to do with the 12 volt system is for the converter. It charges the battery and supplies 12 volts for the 12 volt system When plugged into shore power,

    Be sure your telling us ALL the things that don't work. What you describe sounds like it is just one fuse blown. Explain how you checked the fuses.
  • Please explain what you are calling the Aux Battery Switch. Circuit breakers are 120 volts so forget about them. The only breaker that has anything to do with the 12 volt system is for the converter. It charges the battery and supplies 12 volts for the 12 volt system When plugged into shore power,

    Be sure your telling us ALL the things that don't work.What you describe sounds like it is just one fuse blown. Explain how you checked the fuses.

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