Rear brake light will not come on. put new bulb

So your taillights should have 2 bulbs in them. 1 that turns on when you turn your lights on and stays on until you turn them off. That same bulb should have a 2nd circuit that lights up when you press on your brakes. The 2nd bulb appears when your reverse gear is engaged. So if you have no lights on right you have to replace both bulbs and if you have no brake light on the left you just have to replace your rear brake light bulb.

Your rear left side combo lost a ground on the part of brake/signal lamps. Just put one more wire between parts.

Two possibilities:

1. Defective turn signal switch; or
2. Defective BRAKE LIGHT SWITCH (most likely).

CHECK THE FUSES

did you check you fuses or relay switch?

The bulbs could still be the problem since they are double filament bulbs.If your high brake light work but not the low ones the replace the bulbs.If none in the rear work then you may need a brake light switch(on the brake pedal linkage).If this is not the case the check for power to the brake light side of the bulb and repair the broken brake light wire.

Work the 4-way flasher switch rapidly in and out several times. It sounds like the combination switch is corroded. 80% of the time you can clear it by working the 4-way switch (may have to use electronic contact cleaner sprayed into switch as well). The brake lights run through the combination switch (turn signal/wiper switch) to the rear bulbs but the third brake light is fed before the switch.

PROBLEM COULD BE IN THE MULTIFUNCTION SWITCH.

check the bulbs.mine were changed and some genius put wrong bulb in and i had exact same problem as you.make sure tail/brake bulb has double steel connectors.my drivers side one had bulb with single connector,i put new bulbs in both sides and problem fixed.hope this helps mate

does the third brake light work when braking ? the bar on the rear window? if not replace brake light switch on brake pedel