No brake lights, no rear turn signals, no backup lights

On my 97 Chevy Suburban, I have no brake lights, tail lights, no rear turn signals (although the front turn signals flash very fast), and no backup lights. The fuses are fine. Where do I look next?

Assuming the lamps (bulbs) are OK, see if it has a flasher unit under the dash that could be bad.

Check your ground wires, one may have come loose.

There is a disconnect back there that is used to put in trailer light wiring, I’d check to see if it has become separated.

The emergency flashers are probably wired to the same bulbs as the turn signals.

Do the emergency-flashers work?