1954 Mercury Turn Signal Switch

[JMFL36]

My driver's side brake light has never worked in the few years I've owned this '54 Mercury. Today I had a chance to trace the fault back to the turn signal switch. With a jumper across the brake switch leads and the turn signal switch unscrewed from the steering column, I am able to get the brake light to go on if I manipulate the switch by moving it around. But the light will not stay on when I return the switch to its place on the steering column. Solder joints and wires at the switch terminals are good, so I suspect I have an intermittent short in the Green-Orange Trace wire in the steering column or a faulty switch. The turn signals work as they should.

Does anyone know of a source for this switch? Or what will interchange with it? Searches of the usual suppliers came up empty. Part number from the 54 Merc book is 1M 14486-A. Or has anyone successfully pulled one of these switches apart and fixed it? Thanks in advance.