bad battery, system wont work on 120AC

Sure, buy a new battery,...even if ya don't need one.
Common sense would tell me to start w/ checking the converter voltage.
If the converter is not up to spec, the new battery won't be new for long !

MEXICOWANDERER wrote:
The biggest fault of novice troubleshooting is folks try to start in the middle and work their way to both ends at the same time. 2nd biggest is to assume the problem always lies with the most complicated device.

The battery is bad? Damned if I know how you can outwit that. Start there. New battery. Then see what the symptoms are or are not...

adkfreeridex wrote:
Wow you guys, I really appreciate all the input. I cant believe how many of you offered your knowledge. My battery was so dead that nothing would work. After being on 120 for 24 hours everything is fully functional. I am going to purchase a new deep cycle for the trip. I think that that with it being so low, it couldn't complete the circuit and the converter would not function.

Do you have a battery disconnect switch and are you using it when parked in storage?

Wow you guys, I really appreciate all the input. I cant believe how many of you offered your knowledge. My battery was so dead that nothing would work. After being on 120 for 24 hours everything is fully functional. I am going to purchase a new deep cycle for the trip. I think that that with it being so low, it couldn't complete the circuit and the converter would not function.

Have you checked your fuses?

The biggest fault of novice troubleshooting is folks try to start in the middle and work their way to both ends at the same time. 2nd biggest is to assume the problem always lies with the most complicated device.

The battery is bad? Damned if I know how you can outwit that. Start there. New battery. Then see what the symptoms are or are not...

Mark the cables, then take a picture with your cellphone
Then remove the battery

BTW
Connections at the battery
If cables are
White and black
White is negative/ground , black is positive/plus

If calls are red and black
Red is positive and black is negative

Most likey you have White and black cables at the battery
And that confuses many people and they connect the battery backwards
Before you replace anything
Check the wiring at the battery
If in doubt, follow the wires see where the go, to ground or to inside the RV
The main positive usually goes to a little box with two studs, that is an auto reset thermal circuit breaker approx 40amps, they do go bad , a new one is a few $$ at pep boys etc..

sfpcservice wrote:
If the battery has an internal short it could cause the converter to trip constantly. I'd remove the battery negative cable, rest the converter and see if it powers up. If so, the battery is the problem.

This.
Every converter will work well enough to power lights (they dont care about ripple/dirty power) without a battery but an internally shorted battery will shut down all 12V.

X2 and mark those cables before you take them off,and make a drawing, clean all the cables before reinstalling new battery ,and charge the batt before installing.

Sam Spade wrote:
YOU NEED A METER

AMEN, Sam!

OP - Does your trailer have a Battery Disconnect Switch and Solenoid? If the solenoid's OFF and you don't have Battery to power it ON, then that could be your answer.

Or, you have one and forgot to turn it ON...?

Get a Battery before your burn out a much more expensive converter charger section trying to do CPR on a dead horse.

If the Battery's still connected, please mark all the cables to be sure to get them onto the new one right.

All the previous answers could be correct.
YOU NEED A METER to check and see which of them is the right one in this case.