[VetteVet]

The turn signals get their power from a different source than the stop lights but the TS switch connects the stop light power to the yellow and dark green brake light/turn signal wires. It also cuts out brake light power to the TS light that is selected to flash or else the light would be on solid.

The brake light power wire is usually a white wire from the brake light switch to the column connector and runs up into the column to the TS switch. Check it for power at the connector with the brake pedal pushed. If there is power but the brake lights don't work then run a jumper from the white wire to the dark green wire or the yellow wire and push the pedal . If they work then the trouble is in the TS switch or the white wire is broken inside the column. It's also possible that the connector is bad or in rare cases the crimp in the wire is over the insulation and not contacting the copper wiring.

If you don't have power on the white wire at the connector then the brake light switch may be bad or the stop tail fuse is blown. Do tails work?

The brown wire in the middle of the connector is constant hot, key on or key off. Its for the hazards so you could use it's power to jump to the white wire and the brakes should light without pushing the brake pedal . If both lights work the TS switch is good.If you select a turn, then one of the brakes should go off and the TS is doing it's job.