12V mode on fridge shorting out

Discussion in 'Refrigerators and Coolers' started by tfischer, Jul 5, 2018.

  1. tfischer

    tfischer Well-Known Member

    We don't normally use our fridge in 12V mode but for the 4th, thought it would be convenient to load the fridge before we went. I had it running for several days on 120V power. I have a cooling fan that was running, and the van was running (with charging wire) as well as the pup battery. Switched off the 120V power and switched on the 12V power, and noticed the fan slowed way down. I have a digital voltage meter right inside the pup door... had my son read it while I tried again. Around 14V before I switched on the fridge, and 11V and falling with it on 12V. Again ,this is with the vehicle running and a pup battery.

    I did a resistance check across the 12V heating element and am getting .7-.8 ohm. I'm assuming that's not correct? Anyone know the value I should be seeing? Anyone know where to find this part? An Amazon listing says to use part 0173722018 but I don't see that anywhere.
     
  2. neighbormike

    neighbormike Well-Known Member

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    Stupid question, but you are sure the tv is charging the pup battery?? I have never run much off my tv so not sure what to expect...
     
  3. tfischer

    tfischer Well-Known Member

    Yeah it does... voltage on meter goes up when vehicle is running.
     
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  4. Sjm9911

    Sjm9911 Well-Known Member

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    Not knowing much about car ellectrical systems, can the van Handel the extra power? Is the alternator big enough to charge both ? I really have no idea......
     
  5. neighbormike

    neighbormike Well-Known Member

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    I guess then I would look at age & condition of the battery itself... Having been on shore power first it should have been charged, but any chance the battery is shot & no longer taking a charge?
     
  6. rabird

    rabird Howdy!

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  7. tfischer

    tfischer Well-Known Member

    Thanks all for the suggestions. I should add more info: The battery is brand new... bought it in May. Charging system is just fine. I totally suspect there is a problem with the fridge itself, which is why I was asking for advice. Would replacing the 12V element fix this?

    If someone would go out of their way to measure the resistance on their own 12V element I would be most appreciative. It's actually very easy to do: Just disconnect all 12V power from your trailer, put a multimeter on resistance mode and poke it against the two 12V terminals coming into your fridge, and turn on the 12V switch. Thanks!
     
  8. tfischer

    tfischer Well-Known Member

    Thanks for that link. That's a pretty expensive part... I'll pay it if it will fix the problem but I'm hoping to nail down that the element is indeed the problem first. Would hate to shell out $75 and still have it not work :)
     
  9. rabird

    rabird Howdy!

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    tfischer likes this.
  10. tfischer

    tfischer Well-Known Member

    Thanks much for that link. What I measured was not nearly as far out of spec from that than I expected... so I did more investigation. If I measure voltage right at the battery, and switch on the 12V fridge, the voltage only drops a tenth of a volt. But if I measure elsewhere on the system, the voltage drop is much greater. So it looks like I have a wiring problem somewhere in the camper, and not a fridge problem. I do know that when people use the water pump, the lights dim slightly, but I figured that was normal. But that might be another symptom of the same problem.

    Since owning the camper 5 years ago I've replaced the converter (2 seasons ago) and replaced all the ground connections with the frame (about the same time). I will need to pop-up and do some additional tests. I'm going to try to use jumper cables to get first a good ground ,and (if that doesn't work) secondly a good power connection from the battery/front of trailer to the converter area. That may indicate that I have to run new wires or something.

    Thanks for the help. This is going to be an ongoing project for me. We leave in a week for a 11-day trip, and this means we won't be able to travel with the 12V fridge, but that's only a slight inconvenience.
     

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