22 - Turn Switched DRLs

I bought a new set of sixteen "Eagle EYE" LEDs on eBay (4 extras). These are slightly brighter than the previous set (110 lumens each versus 70 lumens each) and consume a bit more power (3 watts versus 1.5 watts). The mounting nuts are a bit smaller, and they are now somewhat less expensive, but otherwise they are the same. Here are the Eagle Eyes mounted and wired and ready to go. I used Krazy Glue to secure the lenses. Also shown are two miniature PCB mechanical relays and a 3-wire connector (both bought from Amazon). I used the connector as a quick disconnect between my car and the front fascia.

Here is a picture of the front right turn signal bulb removed from the socket. A quick test reveals that the turn signal bulbs have a constant ground and that the power is switched on and off when the turn signal lever is activated. In this case, the blue wire with the red stripe is the power. The front left turn signal bulb is similar but uses a different color power wire.

This circuit diagram shows how the turn-switched DRLs work. When the front turn signal bulbs are off, the relay coils are not energized and the DRLs light up as normal. If either of the front turn signal bulbs are powered, the relay coil for that side is energized and power to the DRL on that side is interrupted for as long as the turn signal bulb receives power. Thus the turn signal and the DRL alternate their blinks, as long as the turn signal is engaged.

This picture shows a new wire being run from the front right hand turn signal bulb along the bumper to the left side.

(The front fascia has been removed.)

Here are the two mechanical relays wired as above, and mounted in the left front wheel well below the battery. I mounted the relays to a steel strap using double-sided foam tape, with a zip tie for added security.

See this YouTube video clip for a demonstration!