Combination stop/tail lights require a selector switch built into the steering column switch assembly. If they use the brake lights for both functions, one brake light will burn constantly on a stop, while the other one flashes to indicate a turn. No turn, both lights are on to signal a stop. The early aftermarket turn signals didn't incorporate that switch. They came in "4-wire" and "7-wire" designs, and the ones with 4 wires cannot be set up to combine turn and brake lights on the same bulb. The "7-wire" switches have an input wire from the flasher, another from the brake light switch, a "pilot lamp" output wire that goes to an indicator light on the dash, and four wires to the bulbs, front and rear, right and left.
Jerry
Last edited by Hotrod Lincoln; 02/23/2010 10:15 PM.
