This sort of points to a converter problem or a battery problem or both.
Do you have a volt meter?
Checking the voltage at the battery with and without the camper disconnect switch turned on tells us a lot.
Then turn on a light and read the voltage with the disconnect on.
Then what is the battery voltage when the converter is plugged into shore power and the battery disconnect is on.
A fully charged battery at rest will be 12.6 to 12.7 volts DC. It may be lower if it is discharged. At rest means not on a changer for at last 8 hours and was fully charged with no load on it.
When the converter is doing something, the battery should be up at 13.25 volts for float mode or 13.65 volt for normal charge. I think yours is a WFCO converter is it not? Some of them may have had a 14.4 volt mode too. Point is if the volts do not rise to at least 13.2 when plugged into shore power, the converter is not doing anything.
See this post at Wannabes just went through this. It may help. Then ask away here on your post for clarifications.
I will be out camping this weekend so it may be a bit to get back to you but others can help too.
Good luck and hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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