I have a 2004 F250 Superduty Crewcab 4X4 with the factory towing package. I have a used camper shell for it without a 3rd brake light. I want to install a 3rd brake light but need to know if there is an existing 3rd brake light wire on the truck near the rear bumper? Thanks.

 

On my '99, the wire was up under the rear bumper on the driver's side. It was a light green wire with the end taped.

 

Found it, "light green wire with the end taped". It was tucked up out of the way. Even had a label on it, "Center High Mount Stop Light".
Thanks for your help.