The reverse lights, or backup lights illuminate when I’ve parked the truck and the lights are still on for the auto headlamp function, and they come on when I use the remote to unlock the truck and the lights come on when the alarm is disabled.
They aren’t on when I’m driving and they come on when I have the transmission in reverse and go out when shift from reverse to drive.
It’s very strange, and for me, who did automotive electrical in a shop for three years with Cadillacs being our most frequent customer, and now I’m an electrical contractor with over 30 yrs in the trade, I have to ask for help. Is there an adjustment on the backup light switch like they always had on the steering column on GM cars? These days with the transmission shifter being only an electric switch as is the accelerator pedal, I wouldn’t be surprised if the backup light switch is on the transmission linkage or on the housing somewhere, like my Dodge Magnum has its transmission shifting electric switch, on the topside of the trans pan mounted next to the dipstick tube.
For all I know, maybe that’s the way the backup lights are supposed to work?