You might have a bulb that is burnt out which will cause your signal light or even tail light to stay on
The most likely cause is the turn signal flasher.
Could it be just a blown fuse. I would check that first.
No, but something that could cause uneven idle could cause the check engine light to turn on.No, but something that could cause uneven idle could cause the check engine light to turn on.
Probably the Electronic Flasher. These ,when the fail,will allow the Signals and/or hazard lights to work intermittently. The flasher is the same for both the signals and hazards.
both left and right blinkers operate off of the same flasher. the flasher is a small module that plugs in usually under the dash just above your left leg as you are sitting behind the steering wheel. a bad turn signal bulb could also cause the dashboard indicator light not to blink.
Sounds like there is a problem with the turn signal switch but it could be another problem. First you need to see if the hazard light's work normally when turn signal is not on, if it does the the turn signal switch is the problem. If your hazard lights do not function when you turn the hazard light switch on, then it's a simple fuse or flasher canister that has gone bad and your hazard flasher is in the on position. If the Hazard light's have a bad fuse or flasher canister and is in the "ON" position it can cause the problem you describe.
Flasher relay is defective.
Check the bulb, it could be blown.
u need to replace flasher can in your vehicle This could happen if flasher had hazzard flasher "on" and could be broken so it will not turn off. (I assume center brake light still works) if so, need new flasher switch in steering colum or find a way to rewire brake lights from brake light switch to rear lights. This is just a guess. Be sure brake light switch is OK.
If none of the bulbs light up check the fuses. If only one bulb is out check the bulb. If the bulbs light up but don't blink check the flasher relay.
A flasher relay can be found at the end of the signal light lever on a steering column. Remove the steering covers and the light flasher will be visible.
If a signal light stays on, but does not flash on a 1989 Pontiac, there could be a light burned out in the turn signals on the exterior of the vehicle. It is also possible that the flasher unit has gone bad. The flasher unit is under the dash on the driver's side.