07carbon3
Junior Member
- Joined
- Jan 27, 2016
- Posts
- 5
- Reaction score
- 0
- Location
- Ontario, Canada
- Ram Year
- 2023 1500 classic
- Engine
- 5.7 hemi
I’m trying to add a pre-wired 3mm LED into the interior door handle bezel on my 2023 Ram 1500 Classic Tradesman. Ideally, I’d like the LED to function like the factory window switch backlighting, meaning it only turns on when the headlights are on.
I started by probing the driver-side door harness with a multimeter, looking for a wire that only receives power when the headlights are turned on. So far, I haven’t had any luck.
I did find that the orange/blue wire has 12V when the truck is switched on, but it stays at 12V whether the headlights are on or off. Because of that, tapping into it would make the LED stay on any time the truck is on, which isn’t what I’m looking for.
I also found a wiring diagram for a 2023 model that appears to show the orange/grey wire as the illumination wire, but I can’t get a useful reading from it or get the LED to light up from that wire.
While researching, I came across some information suggesting that the window/lock switch assembly may be controlled through LIN bus communication rather than a simple switched illumination wire.
From what I understand, the Body Control Module may send a digital signal to the switch module, and the internal circuit board inside the switch then controls the factory LEDs. If that’s the case, there may not be a separate external illumination wire in the door harness that can be tapped into directly.
I’ve also seen references to PWM control, which may explain why the multimeter readings are confusing or not showing what I expected.
Has anyone successfully wired an added LED in this area so that it behaves like OEM illumination and only comes on with the headlights or interior backlighting?
If so, where did you tap power and ground from? Did you find a true illumination source in the door harness, or did you have to pull the signal from somewhere else?
I’d also appreciate any confirmation on whether the door switch illumination is LIN bus or PWM controlled on these trucks, since I don’t want to tap into the wrong wire or cause issues with the switch module.
Any advice, wiring locations, or examples from anyone who has done this would be appreciated.
I started by probing the driver-side door harness with a multimeter, looking for a wire that only receives power when the headlights are turned on. So far, I haven’t had any luck.
I did find that the orange/blue wire has 12V when the truck is switched on, but it stays at 12V whether the headlights are on or off. Because of that, tapping into it would make the LED stay on any time the truck is on, which isn’t what I’m looking for.
I also found a wiring diagram for a 2023 model that appears to show the orange/grey wire as the illumination wire, but I can’t get a useful reading from it or get the LED to light up from that wire.
While researching, I came across some information suggesting that the window/lock switch assembly may be controlled through LIN bus communication rather than a simple switched illumination wire.
From what I understand, the Body Control Module may send a digital signal to the switch module, and the internal circuit board inside the switch then controls the factory LEDs. If that’s the case, there may not be a separate external illumination wire in the door harness that can be tapped into directly.
I’ve also seen references to PWM control, which may explain why the multimeter readings are confusing or not showing what I expected.
Has anyone successfully wired an added LED in this area so that it behaves like OEM illumination and only comes on with the headlights or interior backlighting?
If so, where did you tap power and ground from? Did you find a true illumination source in the door harness, or did you have to pull the signal from somewhere else?
I’d also appreciate any confirmation on whether the door switch illumination is LIN bus or PWM controlled on these trucks, since I don’t want to tap into the wrong wire or cause issues with the switch module.
Any advice, wiring locations, or examples from anyone who has done this would be appreciated.
