The thing to remember when diagnosing lighting system problems is that the lamp may not be the culprit. Never automatically assume that because it seems as though the lamp has failed, it’s the lamp’s fault-you must determine the root cause of the problem so that more serious lighting system problems don’t occur.
Brad Van Riper, senior vice president and chief of technology, Truck-Lite Co., said that the natural inclination has long been to assume that the light has failed when it no longer functions.
“People have been conditioned to this approach with home lighting and passenger car lighting by automatically replacing the bulb when they see a failure, but in the heavy-duty lighting market, this may not be the right thing to do,” he said.
Therefore, it’s vital that you find the root cause of the lighting system problem promptly while not assuming it is the lamp that caused the failure.
When troubleshooting the lighting outage, use a multimeter to analyze the system. “Check first for the presence of a ground at the lamp assembly, then look for the voltage at the lamp connection. The last step is to check the lamp assembly,” he explained.
You then should be able to isolate whether you have a ground, power or a filament issue.
“This simple troubleshooting process could decrease your customer’s lighting cost by as much as 40%, if he has a typical application,” Van Riper added.
Because keeping costs down for your customer should be one of your top priorities, you want to make sure that you service his vehicle right the first time he brings it in to your shop.
