Could someone explain to me how the brake lights work on my 70 Chevelle? I have no brake lights and I have checked the fuse (OK), I checked the switch on the peddle (OK), and I checked the bulbs (OK). So next I pulled out the schematic and looked at the wiring diagram. I understand the wiring colors and ran then down by taking apart the connection in the trunk. Left turn is Y, right turn is DG, back-up is LG, fuel is T and the running lights are BR. These all work correctly but there is a lower voltage on the running lights (BR) wire. I assume this lower voltage is correct?? Or do I have a problem there? Now, how do the brake lights come on? Do the brake lights work on a higher voltage when the brake switch is engaged? If so, then the higher voltage would have to pass through the white (W) wire coming from the brake switch, but where does the white wire go and how does it connect into the running light BR wiring system?? Thanks for any assistance on this - Charlie

Charlie,
look closer at the schematic. the white wire should go into the turn signal switch...activating both turn/brake lights.
do your 4 ways work?
david

No my 4 ways do not work. Yes, I see on the schematic that the white wire goes into the turn signal bundle so now thinking that the brake lights work on the turn signal wires. So, if I don't have 4 way's and no brakes then the turn signal switch might be bad??

All operate on the same voltage.

Yes, I see on the schematic that the white wire goes into the turn signal bundle so now thinking that the brake lights work on the turn signal wires. So, if I don't have 4 way's and no brakes then the turn signal switch might be bad??

Correct.

well let me save you some sleepless nights mine 72 el camino ss did the same thing check your fuse box make sure the fuse holder is clean for the tail lamp the fuse might check good but might not be getting full contact and make sure it is holding the fuse tight i replace my turn switch and replace the wiring in the floor before i found mine take your test light and touch the the fuse prong and not the fuse if this checks out then it is your turn switch i hope this is some help:yes: