Fully charged battery, No lights,radio,nothing ???

[dalejiw25]

I have a Ultra III power center with a fully charged battery(single 12V.). When hooked to shore power the inverter seems to function fine as far as the fan kicking on when things are being used however when unplugged from shore I have nothing. I can't find any in line fuse from the battery or any salesman switch or key. Any suggestions will be greatly appreciated. Thanks.
This unit is covered under warranty but it's Saturday and no one is there. Just wondering if it could be something simple I'm overlooking.

[dalejiw25]

Thanks Roy. I checked everything out with the voltmeter and all seems OK. When I replaced the fuse I noticed the cover was off it. May have gotten some water up in there and blew it. I put some Di-electric grease on the cover when I replaced it, Hopefully that'll do the trick. Thanks again.
Dale

[RoyB]

DALE - This usually just doesn't blow by itself.

Before replacing fuse you need to first check the case on the single 12VDC battery and look for the word NEGATIVE or NEG or the symbol (-) stamped on the case. Then hand trace this connected battery cable and make SURE it goes to the TRAILER FRAME GROUND real close to the battery terminals.

You may have accidentally REVERSED the battery terminal connections. If this has happened then you may have two more blown fuses on the 12VDC Distribution Panel labeled REVERSE POLARITY. These are usually two LARGE VALUE ATC type plug in fuses sitting by them self away from the other 12VDC fuses.

Correct the battery terminals first and then replace the blown fuses otherwise it will just blow them again. Only takes one little bitty spark...

We all have done this at least once...

I always do a quick check when I do things around the battery terminals where that I will measure across the battery terminals when not on shore power and will read 12.5-6VDC when the battery is fully charged. Then I check for interior lights being on inside the trailer. This tells me my battery and fuses are working correctly. Then I can connect the shore power cable to 120AC and I will see the battery terminals jump up to 13.6VDC and the ceiling lights may get a bit brighter. This tells me the on-board converter/charger is working and all fuses and connections are correct.

Roy Ken

[dalejiw25]

You guys are the greatest. I found the in-line fuse on the frame rail and it's blown. Will replace and hopefully all is well. Thanks again. Much appreciated.
Dale

[dalejiw25]

Thanks. will check and get back.

[westend]

Check to see if there is an inline circuit breaker close to the battery bank. It is usually a small metal can affair and may have a reset button.

[Old-Biscuit]

Your 'converter' (converts 110V AC power to 12V DC power & charges battery) is supplying your 12V DC system when plugged into shore power.
When unplugged from shore power your battery should supply the 12V DC system

You need to check a couple of things
Check on 'converter' for a couple of large amp fuses 'Reverse Polarity'. If those fuses are blown then converter can not charge battery and battery can not supply DC system.
Also follow positive cable from battery to converter and look for a in-line fuse/circuit breaker.

Could look like this........and could be mounted on trailer frame or in battery compartment. Small button on side is 'reset'