2003 Ford F-150 brake lights

Brake lights stay on when running lights are on but work properly if the passenger blinker is switched on, the blinker does not it just stays on. Lights and blinker all work fine if running lights are turned off

Reads like you have a bad ground.
Also, If you have a trailer plug on your truck, make sure the wires to it are not rubbed bare, usually around the trailer hitch, especially if your plug wire is wrapped around it.

Duplicate post. Everyone who can read this can also read the earlier post, @bbrown12440_170440 bbrown. Did you not like the answers you got?