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.
Here are three short movies of this module in action:
the module. It controls the operation of both front directional signal
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. You will also need some wire taps. Although you may receive them with the module, it's best not to use the fold-over-and-crunch "Scotchlok" type taps—really, please don't; you'll regret it later. You'll have a much better, more durably trouble-free result if you use Posi-Taps, as reviewed here. If you'll get this assortment, you'll surely find uses for them (they're one of those products that you buy for a particular project, but then other uses for them keep popping up in front of you once you have them).
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
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.
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
This is optional. 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:
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—just like a factory installation. This allows
for the engine to be running without the DRLs operating when the car is
So: Ignition switch ON, parking brake APPLIED means power across
relay 86/86, which means no continuity between 30 and 87a. Module
has no ground, so DRLs do not light.
Start the car (and release the parking brake, if you've tied into it). Both front turn signals should be steady-lit. 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.