Contact me to buy the DRL-1 module.

The DRL-1 Daytime Running Lamp module provides a fully automatic Daytime Running Light function by operating the vehicle's front directional signals steadily, except when they are flashing as turn signals. This DRL implementation complies with US and Canadian DRL performance requirements, and has major advantages over headlamp-based DRLs. Because directional signals are legally required to shine light in a wide angle, the DRLs are visible through a wide horizontal angle for maximum conspicuity and safety benefit in avoiding angular collisions with pedestrians, bicyclists and other motorists. Turn signal bulbs cost much less, consume much less power and have a much longer lifespan than headlamp bulbs. There is no undue glare with turn signal DRLs, as can be a problem with headlamp-based DRLs. And, it's much harder to forget to turn on your full lights at night, because the DRL color is amber rather than white so you don't see misleading reflections of your "headlamps" (actually your DRLs) in shiny surfaces after dark. All of the vehicle's original lighting functions—turn signals, hazard flashers, parking lamps, etc.—carry on working as they always have.

This compact, dependable module, when installed properly, will give years of trouble-free service. The module comes with all the necessary connectors and can be installed under the hood, under the dash, or near the right or left front turn signal on a vehicle of just about any make, model and year.

Here are three short movies of this module in action:











This is the module. It controls the operation of both front directional signal lamps.

You will be making four connections to existing wires on one side of the car, and only two on the other side. The module's red and brown wires will connect to the cut ends of the front turn signal feed wire on one side of the vehicle, and the module's pink and violet wires will connect to the cut ends of the front turn signal feed wire on the other side of the vehicle. Most installers choose to mount the module on one side of the car, tucked out of harm's way (e.g. inside the front bumper cover, behind the lamp housing, or in one front corner of the engine bay), then extend the correct two module wires over to the other side of the vehicle. Some installers choose instead to access the applicable wires inside the passenger compartment, under the dash at the base of the steering column. This can be a good decision for vehicles operated in severe conditions.

In addition to the connections at the turn signals, you will need to locate a wire that is live with +12v when (and only when) the ignition is switched on. Many cars have a fusebox in the engine compartment, and you can often find an appropriate circuit there. If necessary, you can run a wire into the interior of the car. Select a circuit that's fused for at least 15 amps. Follow the step-by-step instructions here on this page carefully to avoid any problems. Before you begin, you may want to look over this photo-illustrated installation to get an idea of how one installer did the job (in this case, an under-dash module mount location was selected).

Installation

Installation should take 20 to 60 minutes. You will need a wire cutter/strippers and a pair of pliers to make the connections. These instructions assume that you will be installing the module near the left front turn signal. If there is more room on the right side of the car or you prefer a mounting location on the right, simply read "left" for "right" and vice-versa in these instructions. Take care to mount the module out of harm's way. It is weather-resistant and splashproof, but it is not waterproof; don't make it go swimming Attaching the module body to the wiring harness of the turn signal will work, as long as it's protected from rain and snow. See that the module is positioned with the wires coming out the bottom, so any splashed water won't seep into the module between the wires. You may lengthen any of the wires in order to place the module in an optimal location. Use #18 or #16 primary wire. It is best to extend wires using wire of the same color, but if this will not be practicable, make sure to mark your wires clearly so you will be able to make the proper connections.

Circuit Diagram

This is the circuit diagram with the module installed:

The White Synchronising Wire

The DRL-1 module can operate in either of two modes; you decide whether you want the left lamp to remain lit steadily as a DRL when you are signaling for a right turn (and vice versa), as is the case with factory-installed turn signal DRLs, or whether you want the opposite-side DRL to extinguish when you are signaling for a turn. Both modes have their proponents and detractors. If the opposite-side DRL remains lit, you have a steady-burning DRL (and its safety advantage) even when you are signaling for a turn. When turn signal DRLs were first proposed in the late 1980s, there was some concern that one steady and one flashing front turn signal could be confusing, but over two decades' high-volume experience with factory-installed turn signal DRLs has shown this not to be an issue.

As you receive the module, it is programmed to leave the opposite-side DRL lit when you signal for a turn, just like factory-installed turn signal DRLs. If that is what you want, then proceed with the installation.

If you want the opposite-side DRL to turn off when you are signaling for a turn, use a quick-splice to connect the white synchronising wire to the green module wire. If you later wish to change to the other mode (opposite-side DRL remains lit when you signal), simply cut the white wire or disconnect it from the green one.


Left Side

  1. Locate the wires for the left front turn signal. If you have a wiring diagram for the car, this will help you identify these wires. If not, then you may need to use a voltmeter or test light to identify the correct wires. Many vehicles have combination park/turn signals with two-filament bulbs. The dim filament is used for the parking lamp function, and the bright filament is used for the turn signal function. These have three wires: one feeding the dim filament, one feeding the bright filament, and one ground.

  2. Using a quick connector, connect the module'sgreen wire from the module to the vehicle's left front turn signal ground wire. If you prefer, you can simply run the green wire to any convenient good ground.

  3. Using a quick connector, connect the module's blue wire to the vehicle's left parking lamp feed wire.

  4. Cut the vehicle's left front turn signal feed wire, and strip ½" of insulation from each end. If your car has side turn signal repeaters on the fenders or sideview mirrors, and/or front sidemarker lights that flash with the turn signals, you want to exclude these from DRL operation—you want only the front turn signals to burn full time as DRLs—so make sure to cut the turn signal feed wire as close to the front turn signal as necessary to be "ahead" of where the sidemarkers and/or repeaters tie into the turn signal feed wire.

  5. Using a wire nut, connect the pink wire to the cut end of the vehicle's left front turn signal feed wire that leads to the car wiring harness. Using another wire nut, connect the violet wire to the cut end of the vehicle's left front turn signal feed wire that leads to the left front turn signal lamp.

Right Side

  1. Using wire nuts, connect the red & brown extension wires to the module's red & brown pair, and route the extension neatly over to the right side of the car.

  2. Locate the wire that feeds the vehicle's right front turn signal.
  3. Cut the vehicle's right front turn signal feed wire, and strip ½" of insulation from each end.

  4. Using a wire nut, connect the red wire to the cut end of the vehicle's right front turn signal feed wire that leads to the car wiring harness. Using another wire nut, connect the brown wire to the cut end of the vehicle's right front turn signal feed wire that leads to the right front turn signal lamp.

Connecting to the Ignition Wire

The yellow wire coming from the module gets connected to a switched power circuit—that is, one that is live with +12v only when the ignition is switched on. Use a circuit that is fused for at least 15 amps. An additional length of wire is provided for you to extend this wire as necessary. Use the appropriate connectors to make this connection.

Tying Into the Parking Brake

For factory-type operation of the DRLs, add a Normally Closed (or Changeover) relay in the module's ground wire. Such a relay can be furnished at the time of ordering the module. Hook it up this way:

  • Module ground (green) wire to terminal 87a of relay
  • Relay terminal 30 tapped into parking brake warning light wire
  • Relay terminal 85 to ground
  • Relay terminal 86 tapped into Module power (yellow) wire

This way, the DRLs are lit when the vehicle's ignition key is on, the parking lamps or headlamps are off, and the parking brake is released. Apply the parking brake, and the DRLs turn off. This allows for the engine to be running without the DRLs operating when the car is not moving, and it works because the parking brake warning light switch grounds that wire when the brake is applied.

Testing

Start the car (and release the parking brake, if you've tied into it). Both front directional signals should be illuminated. Activate the left turn signal and see that the left signal blinks. Cancel the left turn signal and the turn signal lights will both come on steadily as DRL again. Repeat the test with the right signal.

Turn on the parking lights. Both turn signal filaments should go off, and only the park filament should be on (together with the car's front and rear sidemarker lights, tail lights, and dashboard lights). Turn the lights off and the turn signal filaments should come on as DRLs. If something isn't working, double check your wiring for errors.

Use the supplied wire ties to neaten up the wires and to fasten the module in position. Take care not to overtighten the tie wraps that hold the module in place, for if you damage the body of the module, the unit may not function properly or may allow moisture into the system.

Contact me to buy the DRL-1 module.