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JustLabs's avatar
JustLabs
Explorer
Mar 20, 2017

Help with lack of 12V power...Updated

I de-winterized our trailer,and we took it out for the first time since last fall. Everything was working normally in the driveway.

Got unhitched and set up at the campsite. Opened the door and heard the propane detector going off. Thought that was weird and before turning on any lights or appliances sniffed around for a leak.

Didn't find anything so I flipped on the lights. The lights were very dim. I checked the battery level with the little dummy sensor used to check black/gray water levels.

All the lights on the panel flickered a couple times and went blank. I had lost all 12V power in the trailer. The only thing left working was the landing gear which is wired to a 50A circuit breaker and then to the battery. The landing gear went up and down with no sign of low/dead batteries.

I plugged into shore power and everything started working properly. I spent some time checking everything I could think of trying to work out the lack of 12V in the trailer.

I was having some coffee Saturday morning when I started to hear a clicking sound. I traced it to the 50amp circuit breaker connected to the landing gear. It tripped and reset about a dozen times and stopped. Checked the landing gear and now they don't work.

Got home last night and started digging around again. I've tested and re-tested everything I can think of. The only thing I've found was the bad 50A circuit breaker. I replaced it this morning and the landing gear is again working correctly

The converter is putting out the correct voltage. All fuses and circuit breakers test good with a test light,and multi-meter. The batteries show correct voltage and test good with a battery tester. Battery connections are clean and tight.

Everything continues to work properly on shore power,and nothing except the landing gear works on 12V

At this point I'm stumped. If anyone can think of something I maybe missed,I'd love to hear it.

I'm going out shortly to pull down the underbelly plastic and see if there is a fuse or circuit breaker I can't see.
  • Follow battery positive cable that goes to converter.
    Close to battery will be a In-line fuse OR DC Circuit Breaker ---most likely 30A or larger
    It has tripped......therefore no DC from battery when not connected to shore power
    When on shore power converter is supplying DC...but no charging of battery
  • Almot wrote:
    JustLabs wrote:
    I'm going out shortly to pull down the underbelly plastic and see if there is a fuse or circuit breaker I can't see.

    No need to pull down the underbelly. 12V fuse box is often bolted to the frame outside, i.e. below the underbelly, somewhere in front end. Usual $3 residential box with holes and all. With automotive resettable fuse. Could've gotten wet, rusty, mice got to wires, or the fuse tripped.


    The resettable circuit breakers are in the front storage near the batteries.
  • Almot's avatar
    Almot
    Explorer III
    JustLabs wrote:
    I'm going out shortly to pull down the underbelly plastic and see if there is a fuse or circuit breaker I can't see.

    No need to pull down the underbelly. 12V fuse box is often bolted to the frame outside, i.e. below the underbelly, somewhere in front end. Usual $3 residential box with holes and all. With automotive resettable fuse. Could've gotten wet, rusty, mice got to wires, or the fuse tripped.
  • DReisinger wrote:
    Do you have a battery disconnect switch, mine is near the door. It can sometimes get bumped and end up disconnecting the DC from the battery


    No
  • Do you have a battery disconnect switch, mine is near the door. It can sometimes get bumped and end up disconnecting the DC from the battery