I would replace the turn signal switch.
Replace the turn signal flasher relay.
You need to replace your turn signal flasher. Check with your Chevy dealer for the location when you buy it.(10.00)
The signal flasher relay may be at fault, swap it with the emergency flasher relay to see.
WHAT YEAR ?????
If neither signal light works, the flasher may very likely be the problem. The hazard lights and the signal lights work off different flashers.
Wrong bulbs installed? Defective or corroded sockets? Bad turn signal flasher?
That's probably because that's the older van and the more original blinkers
The Relay for the blinkers on a 2000 Cavalier is under the drivers side of the dash. It is mounted close to the kick panel .
Most likely you have a flasher that needs to be replaced.
Check the fuse
Your blinker is bad, it is located under the center of the dash, get to it by taking the driverside lower panel off. There are two one for the turn signals and one for four ways. Blinkers are not that expensive, i got mine at ace hardware
Turn signal flasher