07/15/2026
🔧 What Is It Wednesday? 🔧
This is a tail light circuit board from a 1997 GMC pickup.
In the 1990s, manufacturers began using tail light circuit boards to simplify the vehicle's electrical system. Instead of individually wiring each bulb, power was routed through a circuit board. This allowed a single wiring harness to supply the running lights, brake lights, turn signals, and reverse lights, making assembly faster, more consistent, and less expensive.
While it was an innovative design for its time, these circuit boards became a common failure point as vehicles aged. Heat from the bulbs, moisture intrusion, and corrosion could damage the copper contacts or burn the bulb sockets, resulting in dim lights, intermittent operation, or complete light failure.
Most modern vehicles have moved away from this design. Today's tail lights typically use sealed wiring harnesses, improved connectors, and, in many cases, LED lighting with integrated electronic modules. These systems are more durable, more efficient, and better equipped to handle the increasing electrical demands of modern vehicles.
Have you ever had a tail light that just wouldn't work, even after replacing the bulb? A failed circuit board like this could have been the culprit!
