side running lights

[kglowacky]

wiring my 78 with a painless harness. Do the side lights on the front fenders run all the time with the lights or are they side blinkers. or both I can wire how ever I want, Thanks

[kipps]

I think I understand this correctly. If not, someone please chime in with more accurate info.

The side marker is wired BETWEEN the two circuits you mentioned. It's a very low wattage bulb compared to the front marker and turn signal filaments. This is very important for proper operation.

When the turn signal filament is lit, but the front marker filament is not, 12v power flows through the high resistance side-marker bulb, illuminates it, and goes to ground through the front marker filament. The front marker filament is a low enough resistance(high wattage) that it doesn't illuminate.

The same thing happens in reverse when the front marker is illuminated, but the turn signal is not.

When both filaments are lit, the side marker bulb sees 12v on both sides, so it's not lit.

The final result, is that the side marker bulb illuminates with the front markers and tail lights, but it also flashes with the turn signals.

When flashing, the side marker will be flashing out of sync with the turn signals. I.E. when the turn signal is on, the side marker will be off, and vice versa.

This arrangement is very picky with LED bulbs. The side marker lights need a bulb that can take current flow in both directions. Common LED's can't do this, unless they include gadgetry to specifically let them do so.