I'm an owner of a sunset trail St 198 RB. Problem: When shore line is plugged in it does not recharge the 12V battery...battery slowly drains and I can't operate slide out, awning or anything else😬 Am a new RVer and would appreciate any assistance.
Sounds like you might have an issue with the converter. If you are plugged in you should be able to operate anything 12v without having a battery attached. I would check to see if the breaker might be off for the converter first. If that isn't the problem then I would check the fuses for the converter. If fuses are good then check to see what the output voltage is of the converter at the battery. If the breaker isn't off and none of the fuses are bad but you have low (bellow 13.4v) or no voltage at the battery then I would say that the converter needs to be replaced. If the trailer is new and still under warranty I would just let your dealer take care of it, if not then it's not that difficult to replace it yourself.
I hope this helps and good luck!