1966 Brake lghts not working

[Condore21]

So one day the brake lights were working, the next day...nothing. Anyone run into this before? The fuse for the stop lights is good. Looking under the dash, I can see the brake light switch. There's a black wire with a plastic connector on one side and an orange wire with a plastic connector on the other side. I also noticed that there are two other black wires connected to the brake switch. Any idea on what those are for? I put a test light on the orange wire and I'm assuming that is the constant 12v. When I moved the test light to the black wire and depressed the brake pedal, it did not light up. I'm 6'1" and really hate troubleshooting under dashboards. Any help with this would be great. Thanks!

 

[Tom Bryant]

If you jump across the two plugs, bypassing the switch, the brake lights should light up. If they do it's the switch. If they don't I'd try changing that fuse even though it appears good.

Tom

 

[c5vetter]

agree with Tom - and if those all check out, then you have a ground problem someplace, and those can be very hard to trace.

 

[Condore21]

Thanks for the advice Tom. After doing a little more research, it appears that the other two black wires that I had mentioned go to a capacitor for the brake switch. Anyone have any experience with these going bad? I'm going to try jumpering out the brake switch first. I really hate climbing around under the dashboard. Lol

 

[JohnZ]

So one day the brake lights were working, the next day...nothing. Anyone run into this before? The fuse for the stop lights is good. Looking under the dash, I can see the brake light switch. There's a black wire with a plastic connector on one side and an orange wire with a plastic connector on the other side. I also noticed that there are two other black wires connected to the brake switch. Any idea on what those are for? I put a test light on the orange wire and I'm assuming that is the constant 12v. When I moved the test light to the black wire and depressed the brake pedal, it did not light up. I'm 6'1" and really hate troubleshooting under dashboards. Any help with this would be great. Thanks!

The stop light switch should have an orange wire (hot 12V feed) and a white wire on the other terminal (feeds 12V to the turn signal switch when pedal is depressed/switch plunger extended). The brake lights are controlled by the turn signal switch - in the "no turn" position, the switch feeds 12V to the bright filament on both sides when the pedal is depressed. In the "right turn" position, the switch engages the turn signal circuit to the bright filament on the right side, and disconnects the feed from the brake light switch from the right side, so only the turn signal works on the right until the turn is completed and the lever returns to the neutral "no turn" position. The left side works the same way.

If you don't have power on the black wire (which should be white) at the brake light switch when the pedal is depressed, either the switch has failed or it needs adjusting.

The other two black wires connected to the brake light switch are from the radio noise suppression capacitor mounted adjacent to the switch, on the pedal support; it has nothing to do with the function of the switch.