EmJay108

I'm in the process of designing my own LED tail lights. After digging through the schematics for the exterior lights and some verification on other posts, it's obvious that the 3 wires on the plug for the lights are as follows. Black: Ground; Yellow/Green: Stop/turn; Brown: Parking lights. Seeing as the brown parking lights wire is shared with the DRLs and markers, I'm wondering what voltage the brown wire typically sees.

At first I thought it would be at a lower voltage to dim the tail lights when you're not braking, but I remembered it was connected to all other markers and such, they wouldn't operate at a lower voltage, would they?
Now I'm wondering if there is any circuitry or resistors built in to the stock tail lights to reduce the voltage from the brown wire, and nothing to reduce the voltage on the yellow/green brake/turn wire. Can anyone verify this?

If no one knows the answer to this, I can figure it out later tonight and report back. I'm just at work now drawing out the schematic for the circuit board while I have nothing better to do.

I'm also attaching a schematic of the exterior light wiring for reference.

v6turbo87

There is nothing to change the voltage to the lights. The brightness is controlled by the wattage of the filaments in the bulbs.

EmJay108

That makes a lot of sense. Thanks for your help.