Step 1 – set the ignition key to the “ON” position, and keep the turn signal switch in the direction with the system blinking fast.
Step 2 – check both the front and rear of the car to identify the direction of the signal bulb failure. A turn signal system is made to operate on a specific resistance, so when there is a bulb failure, this resistance changes causing the system to operate at a faster pace.
Step 3 – Disassemble to change the non-working bulb with new one, reinspect the operation of the blinker system before you reassemble.
A flasher system is built into the turn signal system and is used to momentarily cause an interruption in the circuit thus creating the blinking action, this flasher has resistance normally similar to the lighting system (front and rear bulbs). So if both left and right side blinkers indicate quickly and all bulbs are working properly, check and replace the flasher unit or relay.