Battery fuse blown

[scottransell]

The 30amp fuse at the battery keeps blowing when I install a new fuse. I shut off the main breaker to the panel and it blew and disconnected the terminal off the battery and it blew.
Is there something I am doing wrong here as I’ve gone through a lot of fuses to still not be able to get it to work right?
I have the power cord hooked up to a 120 plug. Don’t have anything really running other then the microwave clock and power to the accessories but when I shut off the main breaker you would think there would be no power to the line anymore?

[Fr8Train]

Sounds to me like there is a definite short. Start at the battery and work out. Look for a pinch, rub, something.

[BrerBear]

Same thing happened to me. Turned out to be the breakaway brake wire had rubbed itself bare on the aluminum where it exited the trailer. This was on a fifth wheel.

[LiftedAWDAstro]

Did you just install the battery? Is it wired backwards? Make sure the electric jack switch isn't stuck and is bottomed out. Then pull all the individual fuses out of the converter and try it.

[BCx213]

Check battery connection Black wire should be on the positive side of the battery, white is your ground.

[scottransell]

well battery is hooked up right what the problem is, is when I plug the trailer into my harness of my truck. not sure if the connector to trailer is at fault or the connector on the truck. The dash is saying there is a fault at trailer disconnect. So far I have tried dipping the trailer connector in vinegar and salt solution to clean up the ends but that didn't work as the fuse still blows and alarm comes on my truck.
I am going to try my brother truck to see if its the trailer or the truck is at fault first then move on from there. Might have to disconnect the plug and buy a new one for trailer if this is the case. Going to disconnect all the wires from the battery, such as brake away switch and electric jack to see if one of them is the issue before cutting the old harness plug off. will keep everyone posted as to what I have found out.

[BrerBear]

If you can get you hands on a multimeter set it to test continuity. Disconnect the battery and 120 volt feed. Test between the 12+ on your trailer plug and ground to trailer. Should not have continuity. If it does there is a short in that line. Also check brake. Those are the two main ones. You can also stick the tester in all the holes. Only continuity should be ground. When you disconnect the battery just make sure the positive wire is not touching the trailer or it will give a false read.

[scottransell]

So did what was said and disconnected power from house and from the battery hooked up multi meter and did the test from the plug power slot, continuity was zero, did the rest of them and all was good until I did the center back up one and multi meter went to overload so it looks like I have a short with the back up lights shorting out or the plug is the issue. It keeps going back to the plug and it is looking a little dirty, even though I gave it a vinegar and salt bath. will keep plugging away as now will look at back up lights and check them out if all goes well then it will be the plug next.
Also my battery was low at ten when I tested it with multi meter I know the house is charging it and when I put it in it was fully charged. the battery was warm when touching it I guess from charging it but also the fan on the inverter was running constant is this normal or is the battery shot and needs a new one as it is a 2014 and pretty sure old owner never switched it.

[TWP723]

Make sure the relay is good.

[LiftedAWDAstro]

If the battery was being charged from the on-board converter and is showing only 10 volts after disconnecting, I would think the battery is bad. Pull it off and charge with a regular battery charger. You can then have your local battery place test the ampacity before just buying a new one.

[scottransell]

So with trouble shooting everything and with the help of everyone I have found the issue. I replaced the 7 prong cord and plug with a new one as I found the center prong had a short in it. While I was chasing the wire back I noticed some electrical tape on the cord? with inspecting I found out someone had nicked the cable and this was where the short was. I replaced the whole cord and plug with a new one, Problem solved and just like new. Thanks for all the help and support

[RoyBraddy]

Like A-TEAM John "Hannibal" Smith says "I Love It When A Plan Comes Together"

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Good work...
Roy Ken