Disable your DRL / AHL lights

Under Construction !

The DRL / AHL system keeps the headlights / driving lights on for safety
reasons, which is annoying if you want to move your truck at
night, without the lights coming on.

AHL

The BCM sends out a 5 Volt signal to the Ambient Light Sensor acts, which acts
likes a resistor, changing resistance with brightness / darkness.
The resistance lowers the voltage, and sends it back to the BCM.
When the BCM reads a voltage at 2.2v-4.7 Volts, it commands the DRL on.
when the BCM reads a voltage at .2v-2.1 Volts, it commands the AHL on.
There is a buffer of about 3-5 seconds between switches, to compensate for
temporary shade and tunnel situations.

Installing a resistor in the place of the AHL ambient light sensor can disable
the AHL system by tricking the BCM into thinking there is daylight outside.
This is a common MOD, however I didn't want to permanently disable the AHL system.
By adding a switch to that resistor and a bypass wire you can toggle the AHL system on and off.

Below is the ambient light sensor schematic as it comes from the factory

Here is that same schematic, modified with the switch.

Here is the harness I built, the tape on the green wire is where the resistor is.

The override switch, mounted in my switch panel.
My first switch was bad, and had an open, end result was a BCM code B2647

Remove the right speaker grille to access the ambient light sensor.
Lower the glove box, the release is on the left top while open,
you need to do this to feed the wires through.

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