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volcomig's avatar
volcomig
Explorer
Jan 05, 2015

Help, don't understand how the 12v system works.

Hi, I am new to motorhomes and to this forum. I just bought an old ford econoline conversion campervan converted by van am era. My electrical accessories are the following: Fridge, propane heater (fan) and lights. These are connected to my auxiliary battery (I have 2 batteries). I have some 12v switch in the camper indicating on/off. When the engine is on, working no issues everything works, but I thought that if I plugged my camper in a house electrical outlet and turn that camper's 12v switch on, all the accessories would work endlessly. But no it is not related to the accessories. All that switch does is activate two outlets that are in the camper. There must be a way to plug the camper and make all the accessories work!! An extension cord with a power bar would do the same as that 12v switch. Just so you know the plug connect my van is a regular house size. 15 amps I assume. Please educate me.
Class B

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  • turbojimmy's avatar
    turbojimmy
    Explorer
    Jan 05, 2015
    Not sure how yours is set up, but nearly all motorhomes act as you've described. Nearly everything that can possibly be 12V is 12V. Lights, fridge, water pump, etc. Things that absolutely have to be 120V for practical purposes are 120V. Things like air conditioners and, as you've found, 120V outlets.

    You have 2 batteries. Typically one is to start the engine and doesn't do much else. The other will be for the "house" - all those previously mentioned 12V things. When the engine is running, it should charge that 2nd battery. When plugged into shore power, a CONVERTER should convert the 120V AC to 12V DC and provide continuous 12V power to your "house" (and charge that 2nd battery).

    So....look for a converter and make sure it's working. They're usually protected by a circuit breaker on the 120V side. Look where your power cord enters the RV and follow it to (hopefully) a breaker box and ultimately to a converter. There should also be a 12V fuse panel for the house that you can trace back to a converter somewhere.

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