How are Turn Signal Switch issues diagnosed?
A technician will first look to rule out simple causes of malfunctioning turn signals - a burned out bulb, a blown fuse, or a faulty relay. There are two turn signal lamps on each side of the vehicle. One in front, and one in back. If one bulb is burned out, the other will still work, but it will blink rapidly. The relay is the true switch for the lamps. It may be removed and tested with a multimeter. Using a diagnostic scan tool, the technician might check the operation of the lighting system by reading data from the Light Control Module. The turn signal switch may be removed and probed with a multimeter to diagnose a problem. The technician will need access to a wiring diagram for the vehicle to determine which wire terminals on the combination switch assembly are used for the turn signal switch.
How are Turn Signal Switches replaced?
To replace a turn signal switch, a technician will disable power to the lighting system by disconnecting the battery or by pulling a fuse. The steering column cover trim and lower dash panels need to be removed for access to the switch assembly. In some cases, this can be an extensive operation that includes removal of trim above the steering wheel and around the instrument cluster. The retaining fasteners are unscrewed and the combination turn signal and headlamp switch module is unplugged from the wiring harness and removed as an assembly. The new module is plugged in and put in place and fastened before the trim is re-installed. The technician will restore power to the system and test the new switch.
RepairPal Recommendations for Turn Signal Switch issues
If symptoms of a faulty turn signal switch appear, the entire lighting system should be inspected by a qualified technician at a trusted repair shop.
What to look out for when dealing with Turn Signal Switch issues