Article is lagging behind. Will be done on Friday, promise!
Rewiring the Jeep Turn signals. The old wiring was interesting.
The side marker bulb socket is isolated from ground. One bulb lead goes to the front marker parking lamp positive circuit. The other lead of the side marker is tied into the front marker turn signal positive circuit.
When the parking lights are on and the turn signal off, the side marker grounds through the front marker turn signal filament and illuminates the marker lamp.
When the turn signal flashes, it interrupts the ground and the marker will flash by dimming. The front marker gets brighter. So they alternate.
When the parking lights are off, the filament which the side marker grounds through is reversed. Thus they blink at the same time.
This works cause the wattage difference in the side marker and front marker. 4W for the side marker and 24W for the front. High wattage filament looks like a low resistance path to ground and the side marker doesn’t send enough current to turn them on.
Problem when you convert to LED. The system works great with LEDs as is. But because LEDs great have a voltage drop they create a little voltage on the turn signal line. This voltage isnt enough to turn on the turn signal markers up front but it does turn on the indicators on the dash. ANNOYING!