Shut truck off, but tail lights do not shut off. Have to unhook battery cables. Has done it once before and IF I recall, I simply moved floor mat a bit and that fixed it. But forgot what I did last time, so this time unhooked battery cables and now when I hook cables back up the alarm system goes off.

Has an aftermarket alarm system on it that could be related to this problem. It has malfunctioned before. Will have it removed.

But meanwhile, does anyone know anything about this problem?

 

Is it tail lights or brake lights? If moving the floor mat fixes it, sounds like your floor mat is creeping up and interfering with your brake switch, which means it's a safety issue and you should find a different floor mat.

 

If it is the brake lights that stay on, you may need to adjust the brake switch or replace if it is defective. Remove switch then manually operate it to see if the brake lights turn on and off. Is the center high brake light on also?

Tail lights are a whole other issue.

 

Sorry....it's the brake lights. And it included my middle upper light as well. And they are fixed now.

We simply uninstalled my aftermarket alarm system and the lights went out. I'll keep an eye out for it to start happening again, then it is time to change that brake light switch.