Warning: This installation article is a tutorial guide. By reading this article, you agree it is for reference and AlphaRex USA nor our distributors make any guarantee on any finished results, nor we held any responsibility for any damage, misuse or personal injuries. If you do not fully understand the installation procedure, we highly recommend you seek help with professional mechanics to do the installation.

Wiring the DRL harness

One of the key features of our headlights is to have the ability to run the DRL strips in the day without having to activate any of your lighting controls manually. The way to do this is by wiring the harness that is included with your headlights.

Depending on the headlights feature you get, there will be two types of DRL harness. For headlights with activation light and sequential signal feature, there will be an extra yellow wire from the harness, and that wire is for manufacturer to use as decode purpose and you can ignore it during installation.

Wiring diagram for DRL harness without Activation light and sequential signal
Wiring diagram for DRL harness with Activation light and sequential signal

The function of the DRL harness is to allow the DRL with different intensity during daytime and night time. Basically, the DRL harness will supply extra power to the DRL for brighter output during daytime, and when the parking light is on, the DRL will be at reduced intensity. With the optional harness installed, the headlights will function as follows with most vehicles:

Ignition/Engine ON – DRL at High intensity
Parking Light ON– DRL at reduced intensity
– amber side marker
Low Beam ON– DRL at reduced Intensity
– Amber side marker
– Low beam on
High Beam ON– DRL at reduced Intensity
– Amber side marker
– Low beam on
– High beam on
Automatic Function– Will function as normal

If you do not wish to install the harness, the only function you will be missing is to have the DRL run at high intensity while your headlights are set in the off position and the engine/ignition is on. If your vehicle’s lighting is set to the automatic setting, all functions will work as normal.

Tapping the grey wire to ignition

With the grey wire, you will need to tap it into a switched fuse under the hood. We recommend that you use a fuse tap similar to the picture below.

Suggest fuse locations

2009-2014 Ford F150 – #79
2015-2017 Ford F150 – #97
2018-2019 Ford F150 – #36
2017-2019 Ford Super Duty – #35
2009-2019 Ram – #F66

2015-2019 Chevrolet Silverado 2500HD/3500HD – #39
2007-2013 Toyota Tundra ING fuse
2014-2020 Toyota Tundra ING fuse
2014-2020 Toyota 4Runner INJ fuse