Jimmie Moreland

Ibra0078

This is what I found, hence why it won't work connecting to a dimmer wire

https://www.f150forum.com/f118/illumination-dimmer-wire-361523/

Kingofwylietx

What about piggybacking the ambient lights for very low power additions.
For larger power draws, pick up an electronic relay and use the ambient light wire as the trigger.

Sharkhunt

This makes sense at first glance. Would PWMd current hurt a relay?

I could have sworn I read someone tapped into the headlight switch in another thread, and it worked for him. After reading the thread linked above explaining that the BCM uses PWM to control voltage/light level, I am surprised that it worked.

I may give this a try if I can find a diagram of the headlight switch. I need a dimmer that is just on or off voltage, so a relay would be just fine. The BCM has fault and overcurrent protection on those light circuits, so you would not likely cook anything just trying to see if it would kick a relay over within tolerance.

Kingofwylietx

If you only need to power a bulb, find an LED replacement for that bulb and go to town. I replaced the LED light in the center console with a much larger LED light, to get brighter light. It works great.

You could do the same thing. LEDs last so long, who cares if it’s always on? Worst case is that you might replace that $5 LED once. If it’s too bright, put a tiny potentiometer in-line with it. If not power from the center console box, then the light in the small cubby with the sliding cover.