My left flasher stopped working suddently

Check it by using your hazard lights. If they flash, the relay is OK and you have a woring issue.

If the right side lights work it means the flasher unit is ok , check for a blown fuse or faulty flasher indicator switch.

It has to be either a bad switch or the flasher has failed

ck your turn signal switch wiring connector because it is more than likely has been hot and melted some connections.

Had simular problem with wife 2000 Jeep Cherookee.
My signal light were not working at all.Check flasher relay under steering colum

In my case the left front turn indicator lamp worked, but not the left rear indicator, although all the lamps would turn on with running lights activated, as well as the backup light and 'night-light' mode. The left rear turn indicator would not work with the hazard lights activated. I tested the combination switch (this is the left/right turn indicator switch you use when driving to indicate which direction you are going and is mounted/located on the steering column) and it tested O.K.. I had good continuity from the combination switch black wire, and resistance on the blue-white wire from there to the left rear turn indicator lamp, as well as good continuity on all wires going out from the left parking light fuse. Since the Haynes manual indicated that the flasher module was probably good if it made the tell-tale clicking sound, I was feeling perplexed. So I took it into a local shop that specialized in auto electrics and it turned out to be the flasher module. I was under the impression that it operated in a straight-forward left-right manner, but apparently it has a different circuit for each turn indicator lamp. So even if it is making the appropriate clicking sound when the combo switch is flipped, it could still be the flasher module. Obviously the manual leaves a bit to be desired in the troubleshooting of malfunctioning turn indicators.

The flasher does not stop the brake lights from working. Check # 18 fuse in fusebox under lower left side of dash. if it's ok, the brake light switch, on the brake pedal arm is next. light green wire with red stripe is hot if fuse 18 is ok. Depress brake pedal, light green with no stripe should have power. if not, replace brake light switch. If light green wire has power with pedal depressed, combination switch under the steering is next. Remove the cover from around the combo switch {under the steering wheel}. depress brake pedal, light green wire should have power. If it does, pedal still depressed, orange with light blue wire & wire with light green & orange should have power. Those 2 wires are brake & rear turn signal wires. { The turn signal switch should be in the middle, not right position or left. while checking for power in the last 2 wires. Good Luck drvolt.

double check your bulbs again, if still good
check your flasher

G

Hello I had the same problem on my 04 monte. After changing bulbs ,checking wires etc. I finally took it to the dealer and they found out it was the hazard switch. After swapping it with a new one all lights, dash etc started working again and have not had another problem