[//<86TA>\\]

i also agree with Paul V and sbmxrdr. Try swapping the wires, see what happens. If it works after switching wires, its a problem with the controller, obviously. If it doesnt change anything, just burn the damn thing, lol.

Its possible to have voltage at the controller output, but due to internal issues in the controller itself, corrosion, wear, ect, adding a load to it will introduce enough resistance to the circuit (the lamp itself and then possible heat buildup from internal corrosion in the controller, which will create more resistance) to drop the voltage down low enough to keep the lamp off. Kinda like draining a swimming pool through a straw vs a firehose to put out a fire, sure there are 5000 gallons of water available, but the straw makes it worthless. Electricity can work the same way.

is it possible to check voltage to ground at the lamp when the brake is being pressed? Across the lamp and from the + side to the chassis?

i could swing by saturday afternoon or sunday and give you a hand if you need it. Give me a call.