1967 Chevy C20 brake lights
 

Recently bought a truck and it has been torn apart and partly rewired. The tail lights work and the blinkers work, but the brake lights do not work. I think it is supposed to have a brake light switch, but there is no place on or near the brake pedal to mount it. I cannot exactly use the schematic diagram because there are so few connectors on this truck compared to what used to be there. Two wires go into the light sockets in the back and the socket itself is plastic. Was the original metal and was that used as a chassis ground? I have two wires running to the rear to use. One gives me 12 volts and the other is ground to chassis. Putting these on the light socket does nothing. What is the concept behind brake lights? Is there more voltage to the filament for brakes than there is for just tail lights?

Re: 1967 Chevy C20 brake lights
 

one wire (brown) is parking light, one wire (green or yellow depending on what side you are on) is the brake light, and also the turn signal.
I don't have a photo of it, but there is a spot on the arm for the brake pedal where the switch is. The schematics won't help one bit as far as location or plug identification... pretty much all of them are like this, I've never seen a profesional schematic that gave locations nor acurate discriptions of the plugs.
Look under the dash again, and look for the brake light switch, it has a white wire and an orange wire going to it, and it should be towards the top of the pedal over the column.
If it is in fact there, unplug it from the switch, and jump it one terminal to the other. If your brake lights come on, then you need a new switch. If they don't come on, odds are it is your turn signal switch.
It wouldn't be a ground, and it wouldn't be a wire under the truck, becouse you already said the signals work, so it is getting a complete circuit, and propper power to the lights.

As for how does it work, the bulb (1157) had two filliments in the one bulb. The smaller one with less resistance is the parking lights, it only gives out 4 candle power...while the brake/turn signal circuit, has more resistance, and burns hotter and brighter, and puts out more like 32 candle power. If you were to upgrade to a 2057, it is more like 40 candles on the bright filliment if I recall correctly.


By the way, welcome to the board from central ohio.

Re: 1967 Chevy C20 brake lights
 

Can you tell me what the problem may be with the turn signal switch? Where is it, and how do I test it? Can jump the brake light switch and the brake lights come on.

Re: 1967 Chevy C20 brake lights
 

If you are jumping the switch, and the brake lights come on, then it is that brake light switch that is bad.