ok first before we rewire things lets change the bulb for a new one. mine was exactly as the OP describes and it was the low filament burnt out which causes the RLU to activate the high beam but at a really low level almost as if it wasn't on at all(had a guy once stop me to see if my light was even working on a poker run once) but was great when I selected high. changed the bulb out and been just fine . try the simple easy things first.
the op has already changed the bulb... and didn't fix the problem.... re read the op