RAY: A customer was in the shop one day with his camper van. And his complaint was simple. His cruise control was malfunctioning. When driven on the highway, it would drop out of cruise and have to be reset, sometimes several times per mile. What a pain! If there were bumps in the road, it was at its worst.

The mechanic was convinced it was a loose connection, possibly a bad ground. So he jacked up the rear end to get the two drive wheels off the ground, started the engine, put the thing in gear, and set the cruise control. He then began to test every connector by shaking and pulling every plug and wiring harness. No luck. He banged on the dashboard, jostled the cruise control switch, even changed the angle of the tilt wheel, checked for ground connections, did all that stuff. No luck.

After half an hour he was getting frustrated. From the inky shadows of the lunch room, Crusty emerged, having just finished his sixth Bavarian Creme donut of the morning. He stood there, coffee cup in hand, his gaze fixed on the rear of this van. He mumbled, "The lights, the lights." We didn't pay attention.

Five minutes later he still hadn't moved. And still he mumbled, "The lights. The lights. The solution is in those lights."

And he was right! What did he see in those lights on the rear of that van that gave him the essential clue?