Bulb Test System — Precautions

1. Bulb test system (when installed) controls brake lights and taillights. The system uses a special relay (brake and reversing light checks) which senses the current drawn by the right and left tail light circuits. There is an imbalance in the current consumed from both sides, for example, when one of the bulbs is burned out, and the relay turns on the alarm lamp and / or the sound signal.

2. It follows from the above that any imbalance between the two lighting circuits can turn on the relay. Such instability can also be caused by installing a light bulb of the wrong power. Sometimes two bulbs from a different manufacturer, although nominally the same wattage, skew the system and give a false alarm.

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