We're going into the final stages of putting the car back together, and now we're having problems with the brake lights.

We have the sequential turn signals in. Both turn signals activate when you switch them on just like they are supposed to, and they come on when you turn on the lights. The right brake light works, but the left brake light doesn't. So everything works except for the left brake light.

Also, when you push in the brake pedal, the left turn signal indicator on the dash glows green. It doesn't blink, it just lights up.

Where's our issue? Thanks in advance.

 

1. Check the ground on your left rear brake circuit.The lamp housings are notorious for corroded joints.
2. Check that the left rear lamp is getting power when the brake switch is on and the turn signal is centered (off)

 

That sounds like you have a wire crossed somewhere. Did you replace the wire harness? Sense the brake light and turn signal use the same filiment you know the bulbs are good. i would suggest checking for power to the bulb. Im willing to bet that you dont have power when braking. Next comes the hard part, you get to trace the wire back to under the dash and find where the bad connection is. You will need to trace back wire 14 on this scematic(if you have stock wiring).

http://midlife66.com/wiring/66exter1.jpg

ETA: Pay close attention to your turn signal switch cause that is where the turn signal indicator and the brake lights tie together.

 

We replaced the turn signal switch and the harness underneath the steering column. We'll check this next. Thanks for the schematic.