Please allow me to post the back story in case any of that has anything to do with current issue. Went to hook up trailer for camping trip. Power tounge jack and slide out not working despite being hooked to 120V. Single tongue mounted battery has has 3.5V and 12V system not working without 120V. Soon discover that power jack and slide out needs good battery regardless of 120V available. Install new battery and all is good. At campground they have a power outage for maintenance and the 12V system isn't powering all 12V systems except for power tongue jack and slideout working fine. No 12V lights, radio, or fridge. Battery voltage is still 12.5V All fuses good; 2 30amp. mounted near battery, 2 40 amps behind converter door and several 15 amps....all good. Battery cutoff switch is in ON position. And finally, all 12V systems work perfectly when plugged into tow vehicle. Any info. on possible causes or areas that should be checked are greatly appreciated...Thank You!

With 15 views already and no replies my bet is others are thinking the same as I, that your post makes no sense at all. :h I've read it multiple times and can't make any sense out of what you're trying to say and can only suggest that possibly your converter has failed. To better analyze this you're going to have to be more precise in what works, what doesn't, and under what circumstances.

ronwalt wrote:Please allow me to post the back story in case any of that has anything to do with current issue. Went to hook up trailer for camping trip. Power tounge jack and slide out not working despite being hooked to 120V. Single tongue mounted battery has has 3.5V and 12V system not working without 120V. Soon discover that power jack and slide out needs good battery regardless of 120V available. Install new battery and all is good. At campground they have a power outage for maintenance and the 12V system isn't powering all 12V systems except for power tongue jack and slideout working fine. No 12V lights, radio, or fridge. Battery voltage is still 12.5V All fuses good; 2 30amp. mounted near battery, 2 40 amps behind converter door and several 15 amps....all good. Battery cutoff switch is in ON position. And finally, all 12V systems work perfectly when plugged into tow vehicle. Any info. on possible causes or areas that should be checked are greatly appreciated...Thank You!I'm a little confused :) Early in your post you say battery voltage is 3.5V then later you say it is "still 12.5V". Sounds like the battery isn't hooked up. Or maybe you hooked it up backwards and blew the reverse polarity fuses.Assuming your RV battery was at 3.5V and connected, I would say your converter has failed . When you plugged into the tow vehicle, it brought the voltage up.Sorry to say, it's time to replace the converter.

As Sound guy says...no sense at all.

Look for a circuit breaker or fuse under the front of the trailer. It is normally located at the end of the umbilical cord from TV. You can follow the positive cable from the battery to same location.

From what I read, OP installed a new battery and now getting 12.5. But, still doesn't have any 12 volt inside and campground has no 120 volt due to electrical problem. Do you have received tech service with emergency road service you can call for some over the phone help? I would try flipping the converter breaker all the way off, then put it back to on? Loose grouhd?

12V system not working... | Good Sam Community

30 Replies

SoundGuy
Explorer
Mar 11, 2018
wnjj wrote:
You missed the parts where he replaced the 3.5V battery and the campground has a power outage.

I'll bite ... what the heck is a "3.5V battery"? :h
ronwalt
Explorer
Mar 11, 2018
Thanks for the replies folks and sorry for the ambiguous post, I was trying to not be long on explanations, just the facts. To clarify, I'm home now, not and urgent situation. Camper has a new battery measuring 12.5V. All 12V systems work while hooked to 110V, all 12V systems work while hooked to TV. Without any 110V power or TV power the 12V systems Do Not work ( except for tongue jack and slide out, they still work). I've checked every fuse and breaker I could find..all good! Tomorrow I will trouble shoot more from below frame and try to verify 12V ON/OFF switch is working. Thanks again!
lawrosa
Explorer
Mar 11, 2018
Sounds like the main power fuse under the camper frame rail...

They look like this..
wnjj
Explorer II
Mar 11, 2018
ScottG wrote:
ronwalt wrote:
Please allow me to post the back story in case any of that has anything to do with current issue. Went to hook up trailer for camping trip. Power tounge jack and slide out not working despite being hooked to 120V. Single tongue mounted battery has has 3.5V and 12V system not working without 120V. Soon discover that power jack and slide out needs good battery regardless of 120V available. Install new battery and all is good. At campground they have a power outage for maintenance and the 12V system isn't powering all 12V systems except for power tongue jack and slideout working fine. No 12V lights, radio, or fridge. Battery voltage is still 12.5V All fuses good; 2 30amp. mounted near battery, 2 40 amps behind converter door and several 15 amps....all good. Battery cutoff switch is in ON position. And finally, all 12V systems work perfectly when plugged into tow vehicle. Any info. on possible causes or areas that should be checked are greatly appreciated...Thank You!

I'm a little confused :)
Early in your post you say battery voltage is 3.5V then later you say it is "still 12.5V". Sounds like the battery isn't hooked up. Or maybe you hooked it up backwards and blew the reverse polarity fuses.
Assuming your RV battery was at 3.5V and connected, I would say your converter has failed .
When you plugged into the tow vehicle, it brought the voltage up.
Sorry to say, it's time to replace the converter.

You missed the parts where he replaced the 3.5V battery and the campground has a power outage.
wnjj
Explorer II
Mar 10, 2018
The converter is fine. He said there is 12V power when on shore power. The simple answer is the battery is not connected to the system. The jack and slides work because they have more direct connections. There’s still another bad fuse, breaker or connection between the battery and 12V load center. Get a volt meter or test light and start poking around. The battery cutoff switch could have failed. Try jumping across it if you can’t check for voltage at it.

The 2 fuses by the battery are probably for the jack and slide that work. The ones in the converter are for when it’s charging. As enblethen suggested, there probably another fuse or breaker.
LadyRVer
Explorer II
Mar 10, 2018
From what I read, OP installed a new battery and now getting 12.5. But, still doesn't have any 12 volt inside and campground has no 120 volt due to electrical problem. Do you have received tech service with emergency road service you can call for some over the phone help?

I would try flipping the converter breaker all the way off, then put it back to on? Loose grouhd?
enblethen
Nomad
Mar 10, 2018
Look for a circuit breaker or fuse under the front of the trailer. It is normally located at the end of the umbilical cord from TV. You can follow the positive cable from the battery to same location.
Lwiddis
Explorer II
Mar 10, 2018
As Sound guy says...no sense at all.
ScottG
Nomad
Mar 10, 2018
ronwalt wrote:
Please allow me to post the back story in case any of that has anything to do with current issue. Went to hook up trailer for camping trip. Power tounge jack and slide out not working despite being hooked to 120V. Single tongue mounted battery has has 3.5V and 12V system not working without 120V. Soon discover that power jack and slide out needs good battery regardless of 120V available. Install new battery and all is good. At campground they have a power outage for maintenance and the 12V system isn't powering all 12V systems except for power tongue jack and slideout working fine. No 12V lights, radio, or fridge. Battery voltage is still 12.5V All fuses good; 2 30amp. mounted near battery, 2 40 amps behind converter door and several 15 amps....all good. Battery cutoff switch is in ON position. And finally, all 12V systems work perfectly when plugged into tow vehicle. Any info. on possible causes or areas that should be checked are greatly appreciated...Thank You!

I'm a little confused :)
Early in your post you say battery voltage is 3.5V then later you say it is "still 12.5V". Sounds like the battery isn't hooked up. Or maybe you hooked it up backwards and blew the reverse polarity fuses.
Assuming your RV battery was at 3.5V and connected, I would say your converter has failed .
When you plugged into the tow vehicle, it brought the voltage up.
Sorry to say, it's time to replace the converter.
SoundGuy
Explorer
Mar 10, 2018
With 15 views already and no replies my bet is others are thinking the same as I, that your post makes no sense at all. :h I've read it multiple times and can't make any sense out of what you're trying to say and can only suggest that possibly your converter has failed. To better analyze this you're going to have to be more precise in what works, what doesn't, and under what circumstances.

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12V system not working...

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