What Does Illumination Circuit of Brake Controller Install Wiring Do

Question:

On a 2011 chevy silverado 1500. The brake controller wires on the truck have 5 wires. To wire up a controller it says not to use the orange wire. What does the orange wire go too, or used for?

asked by: Hank

Expert Reply:

The extra wire is referred to as the "illumination circuit" which is used to light up the display of a backlit controller. So this circuit is active when the running lights are on to light up the controller similar to gauges on a vehicle dash. Since basically all brake controllers nowadays don't require this it's not needed.

expert reply by: Jameson C