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So my friend has a 91 ss 4eat ive been looking at recently trying to help bestow my personal SS repair experiences upon. After suggesting a few things like new oil sender gasket (leaky) and knock sensor (throwing code) i come to discover his brake lights dont work at all. His driving lights work fine, the bulbs are good, and the fuse is good. The spoiler light doesnt work either.

Im planning on taking a multimeter and checking the brake switch but does anyone have any ideas of what else to check? Also is there a relay hidden somewhere for the lights.

Check the brake pedal switch

switch was bad, so i replaced it but it changed nothing. lights still dont work. Do these lights depend on the shift interlock unit to work? His interlock solenoid isnt switching either. I show 12v on the always hot line going to the brake switch and i show continuity through the switch when its released. Ideas?

anyone?