Thanks for the post! I have been struggling with this same problem.
Could you describe what you mean by A-B switch? Where did you get it and the cables you used?
I have to remove the front TV to repair the damage to the TV cabinet that occurred on my trip to Texas so it would be a great time to fix the connections.
A picture would be a great help.
08 Destination 39W
12 Chev Sonic in tow