Light Bulb Testing System — precautions (Mazda Capella GC)

1. Light bulb testing system (when installed) controls brake lights and tail lights. The system uses a special relay (checking the brake light and reversing light) which senses the current consumed by the right and left rear light circuits. An imbalance in the current consumed on both sides occurs, for example when one of the light bulbs burns out, and the relay turns on the hazard warning light and/or the sound signal.

2. From the above it follows that any instability between the two lighting circuits can activate the relay. This instability can also be caused by installing a light bulb of the wrong wattage. Sometimes two light bulbs from different manufacturers, although nominally of the same power, create an imbalance in the system and give a false alarm.

3. The wiring for the trailer socket must be arranged so that the current for the trailer lights does not go through the test relay, which may otherwise give a false signal. Obtain a Mazda wiring harness kit designed for your vehicle or consult an auto electrician.

(Article is based on website data: MazBook)