This running light/turn signal light is a good example of a simple-looking operation that is easy to get wrong. Here, the running light (but not the turn signal) shares the circuit with the side marker light nearby. The socket also carries the wire for the turn signal circuit—separate from the marker light. Note the jump start booster box in the lower right corner. It was used to help verify the wiring. Here, Aschtgen uses heat-shrink tubing and a heat gun to seal the connection from the elements.