Electrical system repairs are the second largest cost segment for overall vehicle maintenance and have the potential to deliver a nasty charge to a fleet's maintenance budget if not properly managed. Corrosion is a constant threat that requires...
Electrical system repairs are the second largest cost segment for overall vehicle maintenance and have the potential to deliver a nasty charge to a fleet’s maintenance budget if not properly managed. Corrosion is a constant threat that requires just as much vigilance to keep it at bay. Doing so requires knowing and sticking to the basics, according to the Electrical System Maintenance panel of experts at this year’s CFMS.
“Fleets pay millions annually in automotive electrical system repair, so it’s important to look at how to reduce that,” said Paul Kirkup, national account manager with Krown Rust Control. One of the main causes of electrical system problems is the damaging effects of road salt and de-icing agents. (Other causes of electrical system problems include abrasion, impact, extreme cold or heat, vibration, flexing, grit and sand, and tensile loads.)
There has been a concerted effort by city and provincial road/ highway departments in recent years to decrease the use of sodium chloride (rock salt) due to its very corrosive nature. This has led to an increased use of calcium and magnesium chlorides as de-icing agents. The liquid magnesium chloride is sprayed on dry pavement prior to precipitation or on wet pavement prior to freezing temperatures.
The biggest issue with magnesium chloride, according to Kirkup, is that it stays wet down to approximately 15% humidity.
“These de-icing agents are highly corrosive and stay around longer creating increased corrosion-related problems for fleet managers. Electrical connections and wire abrasions get coated with salt, which draws in moisture, creating a breeding ground for destructive corrosion,” Kirkup emphasized.
Removing the de-icing agents can be challenging because they need to be dissolved quickly in order to get the vehicle back on the road and the dissolved salt must be made inactive. The best solution is routine maintenance, according to Kirkup, and includes the following:
• Regular washing with a good cleaning detergent capable of removing the de-icing chemicals from the wiring. Soaking down the vehicle with a detergent then powerwashing thoroughly will reduce the ability for de-icing chemicals to draw in the moisture and accelerate the corrosion process, Kirkup said.
• Applying penetrating lubricant with a high dielectric strength to problem areas on the electrical system such as plugs, wiring harnesses, battery terminals, exposed wiring and the ECU. Spray any fitting joining the wires and wiring harnesses. Pop light fixtures and spray the fitting at the back or drill the box area behind, spray it and plug it with a 3/8 plug, Kirkup advised. Spray also all exposed metal connections and under the battery tray. Keep in mind that over time all fittings start to loosen somewhat and this could allow moisture to set in. To combat this effectively, a complete cleaning of suspect areas should be followed by a thorough application with a high-dielectric lubricant. Also, all starters, generators, alternators and other wired units should be sprayed on all connectors and housing bolts. Consistency is key. Spraying the fittings, connections and surrounding area should be done on a regular basis as part of a preventative maintenance program. Kirkup advised developing an “A”, “B” and “C” maintenance schedule with regular spraying included.
Jason Grins from O.C. Transpo focused his remarks on the heart of the electrical system: the batteries. A good electrical system maintenance plan begins with keeping batteries and connections clean, he said, echoing Kirkup’s comments, and added an important insight: “A clean vehicle does not necessarily mean a clean electrical system.” You’ve got to get under the box cover and check into things close up.
“Washing batteries is critical -out of sight, out of mind gets you into trouble. Batteries need to be cleaned at least every PM session,” Grins said.
Grins also had advice to deal with battery startup issues, offering several tips:
Tip #1: A job done right requires the right tools. For Grins, that means having the following on-hand and in good working order: battery charger; battery load tester (calibrated yearly); infrared thermometer; wire brush (brass is best); charge and check adapters; water and hose for cleaning batteries; and adequate charging, testing and storage areas for batteries.
Tip #2: The inner jam nut is often a culprit when a battery fails to start. It needs to be checked for tightness at every PM, Grins said. The starter mounting bolts should also be inspected during every PM, as should all cables.
“Loose connections are the worst enemies of charging and cranking systems. Why? Loose connections allow corrosion to travel, increasing circuit resistance,” Grins pointed out. “Clean, secure, properly sealed, corrosion-free connections are the key to eliminating no starts.”
Tip #3: Routing and securing wires properly is also important. Proper securement eliminates vibration chaffing.
Tip #4: The current draw test is an inaccurate way to test starters. Amps can range from 650 up to 2,000. For the current draw test to be valid, the following factors must be known: oil temperature, oil viscosity, battery capacity, battery age, battery state of charge, circuit resistance, and engine condition.
Tip #5: If all batteries and circuits test well and the starter is not operating properly, then the starter should be removed.
Tip #6: Consider the costs involved. How long would it take to recharge a totally discharged battery at 0F? At a battery recharge rate of 14 volts at 0F, it would take more than 100 hours. A battery at 0F will only accept two amps per hour.
“A quick boost is a costly decision,” Grins emphasized.