Hello, so I have issues with my 69 mustang.

Brake lights do not work, neither does horn, instrument cluster, or instrument lights.

Trying to isolate each issue.

Regarding the brake swith. I have tested and have continuity from headlamp switch to one side of the Brake light switch (brand new headlamp switch). However, when the battery in and headlamp switch in plug there is no power to that side of the Brake switch. The other side has continuity from there to the rear.

The fuel gauge...

1969 Mustang Brake Issue