Need to clarify what you mean when you say there's "voltage present at both fixtures".
Did you verify there was 12vdc present to power the 1) left running light, 2) right running light, 3) left brake/turn signal light, and 4) right brake/turn signal light?
Where did you place the voltmeter's positive and negative leads when you made these voltage checks?
Curious, are your trailer brakes working properly?
Trailer brakes work, as do all the amber marker lights. None of the four red marker lights work.
Used a meter to pull 12V at each plug. I would have thought something (markers) would be lit up. I grounded on a screw; affixing the fixture to the trailer. Now that you got me thinking....there would be TWO hot leads right? Marker + Brake?
As far of changes. When the trailer was winterized the water pump was replaced under the sink. When I got to the destination last Thursday I could not extract the electric cord. After pulling off the outside plastic housing, and peering inside with a flashlight....there was a loose board tangling the cord. I don't know where this board came from but it has one plastic cable loop wrapped around some wires and screwed to the board. I will have to pull the fuse box from the inside in order to look/fix this board.
X2, On my HTT, the ground wire goes through the wall and down through the floor and is grounded to the TT chassis, basically under one of the tail lights. If I recall both tail lights have a common chassis ground.