Left rear signal and tail light stopped working tried a new bulb

Check front signal bulbs.

The bulb has two filaments; one for brakes and turn signal, the other for tail lights. One filament is probably burned out. Replace the bulb with a new one

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

1) Open trunk
2) Remove small round plastic access panel with a flat tip screw driver by prying open
3) Remove flat tip screw holding tail light assembly
4) Remove tail light assembly by pulling outward, careful not to break plastic guide/nub
5) Disconnect wiring connectors
6) Remove plastic housing access plate on back of tail light assembly by twisting/turning tabs until they click and then lift access plate from tail light assembly
7) When viewing the the bulbs, the turn signal bulb is the bottom left bulb
8) Install in reverse order, ensuring tail light seal seats properly during installation

Replace bulb

Sounds like you lost the ground to the rear lights.

Fast flashing dash signals mean there is a bulb issue-DEFINATELY!

any increase in bink speed is direcly related to a bulb being burt out.

Are all the other lights working, tail, stop and hazard?
Let me know.
Regards,

Rear lights are double filament bulbs one side for the lights other side for the brake/turn signals so it still may be a bulb. Do u have a test light or volt meter you can check to make sure u have power there when brakes or turn signals are activated. Or just try another bulb.