Today’s lamps and harnesses are asked to perform a number of tasks. Effectively fighting corrosion and doing so in a cost-efficient manner is perhaps the largest task asked of today’s products.
“Corrosion is a big concern for truck fleets, and the electrical system is a place where it can do lots of damage, resulting in costly repairs,” says John Jacobs, vice president of research and development at Phillips Industries. “The electrical system, wire, connections, etc., can be compromised when water leaks in and corrosion is allowed to build up.
“Once moisture penetrates to the copper wiring, you’re pretty much done,” Jacobs adds. “When given a gateway into your electrical system, the copper wiring soaks up moisture and contaminants like a dry sponge. On a truck, wiring heats up and cools down on a constant basis. When the wiring heats up, it expands; when it cools down, it shrinks, sucking the moisture in.” Compounding the problem of corrosion are new roadway deicing chemicals.
“Lighting and harnesses are in the top-three maintenance cost areas, and corrosion is the biggest culprit,” says Tim Gilbert, corporate director for OEM sales at Peterson Manufacturing.
“The mix of chemicals being used to treat roads today is very corrosive. As equipment travels it picks up these mixtures, which get into places where it’s not easy to wash out. Even if the chemicals dry, they reactivate when wet.”
Brad Van Riper, senior vice president of R&D and chief technology officer at Truck-Lite, serves as chairman of the Technology & Maintenance Council’s corrosion control task force. He says one of the biggest opportunities in improving corrosion resistance in a lighting system is to eliminate weak links when spec’ing vehicles.
“This is sometimes a forgotten area because of pressure to reduce cost,” Van Riper says, “but it’s also an area where fleets have the most to gain, especially in operations with longer trailer trade cycles. Fleet managers who know their costs are driving specs toward the overall cost of ownership.”
Van Riper is also quick to note that better installation procedures by OEMs are improving lighting system life. In addition, he points to technologies such as hard shell lamp connectors with newly designed seals, better sealing of lamps, and potting of circuit boards as providing more effective barriers to corrosion.
“The trucking industry adopted dielectric grease to prevent connectivity failure in harnesses and related wiring on heavy-duty trucks and trailers,” says Tom Draper, marketing manager at Grote Industries. “Coupled with high-quality connector designs, its protective properties allow equipment to operate over long periods of time in the face of ever more corrosive salt-based solutions used on North American highways.
"When used correctly with dielectric grease, harness connections can remain free of corrosion over the lifetime of a trailer,” Draper continues. “The idea is to never compromise the harness by adding ways for salt to come in contact with the copper wiring and wick through the system. Modular harnesses also give you the ability to change or add to the harness without adding a splice, which can add a salt gateway to the wiring if not done correctly.”
Engineering lighting systems to resist corrosion, even if exposed to contaminants, and minimizing the opportunity for contaminants to enter their lighting systems in the first place is also the goal at Optronics International.
“We employ surface-mount device (SMD) designs for LED lamps to remove vulnerabilities from the corrosion equation,” says Brett Johnson, president and CEO. “In SMD designs, LEDs are mounted directly to the surface of the circuit board, eliminating exposure to connecting points.
“In addition,” Johnson adds, “female receptacles in back of the lamp housing are completely sealed, and inside the lamp a solder point connects wires to the backside of the closed female pin receptacles. The wires carry current to the lamp’s circuit board by traveling through a waterproof silicone-based sealant that prevents any foreign substance from traveling up the wire path.”
In the end, effective designs and proper assembly, especially when maintenance and repair procedures are performed, are the key to ensuring the integrity of today’s vehicle lighting systems.
“Protect the integrity of the entire lighting system,” states Peterson’s Tim Gilbert, “and you will lower the total cost of ownership.”