Keeping the lights on

Corrosion is often the culprit of inoperable lighting during the winter months. The salt, sand and sludge road crews put down to fend off ice can wreak havoc with your electrical systems.

“All exterior electrical interfaces are subjected to both the moisture and the aggressive chemicals used during winter,” said Mark Blackford, Grote’s national fleet manager. “All electrical connections will need protection of utmost quality to deter the initial stages of corrosion. Lighting can be dramatically impacted if the harness/pigtail system is not designed specifically for the brand of manufactured lamp.”

Blackford noted that once corrosion has penetrated the harness system, the integrity of the entire harness is susceptible to current and future problems. So what should fleet managers focus on to ensure a proper connection?

“The easiest point of entry for corrosive contaminants is at overmolded connectors, regardless of the type of connection,” said Tim Gilbert, Peterson Mfg. Co.’s corporate director of heavy-duty sales.

Tom Begin, director of innovation and emerging technologies for Phillips, echoed that in the J560 plug and socket are most susceptible because it is frequently exposed to the elements and can trap moisture and contaminant.

“Because the seven-way plug and socket are designed to industry standards and is interchangeable, there is a gap which can allow moisture to make its way to the front of the plug and socket where the corrosion can occur,” Begin said. “Wiring, which is powered more frequently, or all of the time, will corrode much faster because of the power being applied. In the seven-way connection, this is the blue auxiliary circuit. Bottom line: if there is an unsealed connection anywhere, it is very easy for moisture to enter. Also, any wiring that is cut or nicked provides an opening for corrosion along with frayed, or worn connectors and plugs.”

Gilbert listed off a few quick tips to prevent corrosion:

• Never disconnect silicone-sealed plugs (AMP, Packard or Deutsch connectors) unless absolutely necessary.
• Repair cuts in insulation or other breaches immediately, since moisture can wick down wires quite far, quite quickly.
• Only use glue-filled, heat-shrink connectors when repairing wiring. And, of course, never puncture wiring with a continuity probe.
• Inspect wiring often, paying special attention to overmolded junctions.
• Ensure wires are routed so that connectors are not pulled taut.

“Keep the J560 plug, nose box terminals, and non-sealed connectors—such as PL10, PL3 and .180 bullet connectors—liberally greased, but do not use dielectric grease on any type of plug that contains a silicone seal,” he stressed. “That will prevent it from sealing properly.”

When it comes to using dielectric grease, some harness systems and LED lamps are designed to use said grease and the designs of those particular modular connections provide reservoirs to hold that grease.

“When properly used, the grease forms a barrier that resists moisture at the connection point,” said Brett Johnson, president and chief executive officer of Optronics International. “However, the connectors must be inspected regularly and the grease replenished as needed. Some fleets even apply heat-shrink moisture barriers to all electrical connections to provide an added line of defense.”

“It is recommended that the seven-way plug and socket be cleaned and dielectric grease be applied [Quik-Shot Dielectric Grease Tubes] at every preventive maintenance interval, on both the tractor and the trailer sides,” Phillips’ Begin said. “Often, there is more corrosion at the tractor side because it is disconnected much less frequently than the trailer side. Use a seven-way plug and socket brush with water only. Do not use soap. Phillips recommends three- to six-month intervals, or more often if the vehicle is excessively exposed to winter, like conditions where deicers are commonly used on the road. After every cleaning, re-apply dielectric grease. This prevents the moisture deposited during the cleaning process from collecting and eventually causing corrosion.”

“Corrosion can also occur be on screws, contacts, terminal blocks, bare copper etc., basically anywhere there is an electrical connection, it is prone to corrosion,” added Heath Million, engineering director for Optronics International. “As an example, a battery will sometimes corrode due to the dissimilar metals between the post and the battery clamp. As electricity flows the reaction causes corrosion. Corrosion can also find a path into the electrical system by starting on electrical box handles, edges, hinges, etc.”

System modularity can help fight corrosion and prevent CSA violations. Attempting to maintain and service a non-modular electrical system requires cutting and splicing of wires, and that can severely compromise the system, Johnson explained. It’s easy for even a seasoned technician to make wiring mistakes. Corrosion-promoting moisture can enter a system through splices and old junction boxes and begin working its way through a vehicle’s entire electrical system.

“Most folks don’t realize that cabling and wiring can act like a wick for moisture,” Johnson said. “Once moisture gets in, it can and will travel through the system.”

Modular systems provide a number of benefits. Flexibility is inherent in these systems, which use standardized connectors that can be snapped together to form in a wide variety of power delivery configurations; electrical systems can simply branch off from a vehicle’s main electrical harness line. To maintain system integrity, the modular connectors use dielectric grease to prevent intrusion from moisture and road contaminants.

“A standardized planned maintenance (PM) program is also generally recommended, which should include periodic examination of the entire vehicle’s electrical and lighting systems,” Johnson said. “Every lamp, wire and harness should be visually inspected and any signs of corrosion, cracks, wear areas and punctures noted and corrected immediately, in order to prevent corrosion from beginning and then spreading. ”

For a deeper understanding, Optronics pointed to its Bright Ideas Technical Training Program, a comprehensive instructional system that provides a fundamental understanding of electricity, vehicle wiring, lighting connections, installation and basic troubleshooting.