Where on the chassis is the ground wire bonded?

[inghamm]

Where on the chassis is the ground wire bonded? I have no running lights, brake lights, turn signals on the trailer. I have tested the Bargman on the TV and it has power. I suspect a grounding issue. Also, I don't think my convertor is working. In the past, I could disconnect the battery and still have 12 volt lights, but now I have 12 volt lights only if the battery is connecting. (I have Solar power charging the battery)

[inghamm]

I found it. Behind a vent kind of thing underneath the tub.