Hi All,

New here and hoping someone might be able to help. Working on our 74 F-350 brake lights. There is power to the green wire, and power to the yellow black wire, when the turn signals are activated, but nothing when the brake pedal is activated.

Everything I've found tells me that the green wire is right turn signal/brake light, and the yellow/black wire is left turn signal stop light. So what I can't figure out is why there would be power coming through that wire when the turn signal is activated, but not when the brake pedal is activated.

I get the feeling it's gonna be one of those "d'oh" moments

Does anyone know, is there a switch somewhere between the brake pedal switch (tested that one and it works as it should), and the connector just behind the actual tail lights? Is there something I'm not seeing?

Thanks for any help!

 

I went thru this on my truck when I first got it.
Turned out to be a burnt contact on the
turn signal mechanism switch in steering column
under steering wheel.
Might be same thing, might not.