1995 f250 with the brake lights on at all times.
Replaced turn switch, no help. Doesn't appear to be turn or hazard flasher.
However, I have 12V on both sides of the Brake Switch. Is this normal? Can't tell from wiring diagram.

 

Do you have a third brake light on that truck? Is it on? That would be wired direct from brake light switch, not through multi-function switch. But... have you checked the actual brake light switch? It sounds to me like its bad. There would only be 12 volts on both sides if its closed creating a circuit....

 

Have a third light, but it's always off, as are the "courtesy" lights on the top rear of the cab.
12V on both sides at brake switch connector, with switch disconnected.

 

Id be pulling bulbs and checking voltages. Wire schematics to find out whats going on. Now I am curious.

 

Yep, one of those Saturdays. I'll let you know what I find

 

Something in dome circuit is shorting to GND, pulling up GND on rear, cargo assemblies.