Start by replacing the Flasher Relay.
Press both blinker directions at the same time.
A simple first step would be to check the fuses to these lights, then go from there.
Check the switch
check the brakelight switch. it is located under the dash where the brake pedal rests. Hey its ritchie. If you can click your blinker down and then they work its you blinker switch,but this is my monte.
It has been my experience that when the blinker comes on but the lights don't blink there is one or more bulbs burned out. If that is not the case check the flasher.
Put on your hazard blinker lights so that oncoming traffic will be looking for a dangerous situation ahead and will drive more carefully.
my daughters 1991 miusbishi montero has no break lights , turn signals or hasard lights . All tail lights and front markers are working. All fuses are cking good and all bulbs are good..Is my blinker switch bad ? capri
check the interior switch for where.
The tail lights are on a separate wiring than the blinker/brake lights. Look for a blown fuse or a broken/loose wire.
cheack the wireing
When backing up more then 30 ft. you are required to activate your hazard lights when backing up. So yes, if you are backing up 100 ft. you have to use your hazard lights.
Have an electrician check the wiring that goes to the brake lights in the trunk of the car.