Troubleshooting directional indicators does not have to be a great deal of work. The system is actually simple in design, but with several items that can cause a problem it can be a timely proposition to sort out. I will break the system down to several parts for a step by step guide to find faulty indicators.

First thing is to understand how this system works. We know that a light bulb glows when power is applied to the bulb and completes a grounded circuit. The directional indicator switch has power supplied by one wire and then directs power to the sided lamp that you select through the set of two wires, one for each side of the car. The second component responsible for this system to work is the flasher unit. This item works when the indicator switch is activated, power is transferred through the flasher unit to the lamp. When the bulb is illuminated its causes heat in the circuit causing the bi-metalic strip to open the contact in the flasher unit causing the lamp to go out. Once the strip cools off it closes and the lamp re-illuminates. This will cycle several times a minute causing the flashing of the lamp.

With that in mind I must point out several items, Firstly make sure that the bulbs are proper items. The incorrect wattage bulbs will cause the flasher to operate too fast or too slow. The second item is to make sure the flasher unit is correct for the car. These are designed to work in conjunction with the number of bulbs and the wattage of them. Often these items are replaced with off the shelf items that may look similar but designed for other applications.

First we would check the fuse. Always start from the beginning, its often where the problem lies. Next will be a check of the bulb sockets in the lamps. When corrosion is built up in the lamp base the power may be interrupted in the circuit causing the lamp to be faulty. If power is at the lamp but light fails to operate check the ground from base to chassis. Lamp bases not properly grounded to body will cause an incomplete circuit. If power is not present at the lamp then check power at the switch. It could be interrupted there or at the flasher unit.

When working on this system make sure that you replace perished lens gaskets, use correct replacement parts, and always follow basic safety guidelines when working on electrical systems. Never cut into your wiring harness to test a wire. This will only be a problem in the future.

If you still cannot find the problem, talk to your specialist or supplier of parts as they can often help with your needs.

Happy Motoring

Shawn Thomas