We are providing all the most valuable information to our fleet technician readers this week with another installment of The Technician’s Log, our blog series that aims to talk about anything and everything trucking and trucking maintenance. In today’s article, we are going to talk about your electrical maintenance program. Considering how technologically advanced today’s equipment is, you must have a robust electrical maintenance system to get the most life out of your fleet.
Take trailers as one example. Most lighting problems on trailers are related to failures or damage related to the lighting and electrical harness of the system. As corrosion builds, these components become more likely to fail. But even worse than trailer lighting is the truck itself. Most electrical truck systems have become highly sophisticated. Whether it be the massive number of micro-processors controlling different aspects of the truck or the sensors or video equipment being used, there is a lot of computing going on.
The Importance of Electrical
The electrical systems on trucks today touch on almost every part of the vehicle. From performance to efficiency and safety, the semi-truck is now a rolling computer with a trailer attached. All these new systems, sensors, camera, and other equipment puts stress on the truck’s electrical system. When you have limited time to diagnose and fix an issue with a vehicle, the electrical system is often a problem.
Any time there is any resistance in the electrical system, it could alter any number of signals and data points the fleet relies upon. With electronics, if you do not have a proper power flow, it could disrupt the data flow. More sophisticated electronic systems require a rigorous and sophisticated maintenance program to keep them properly maintained. All too often technicians replace a battery or another component when the problem was in the electrical system the entire time.
One of the best ways to ensure your vehicles’ electrical systems stay in good shape is to follow the American Trucking Associations’ Technology & Maintenance Council Manual. Shop technicians should conduct a thorough assessment of every aspect of the system. But what should this assessment include?
Here’s our recommendations:
- Understand the basics of how electrical systems work.
- Know how to read simple electrical wiring diagrams.
- Study up on what specific electrical symbols mean.
- Be able to perform circuit measurements with a volt-ohm meter.
- Solve basic circuit equations.
- Understand how the data bus on a truck works.
While many fleet technicians have an adequate knowledge of how electrical systems work and how to use a multimeter, there tends to be an information deficit when it comes to electrical analytics. If a multimeter provides a particular reading, will we know what it means? Many truck drivers also have a knowledge gap where the data bus is concerned.
There are plenty of real-world examples where technicians couldn’t analyze a circuit correctly or understand the implications of a meter reading and it ended up costing the fleet more money than is should have. If you don’t have a robust battery or electrical maintenance program, you may wind up spending $5,000 on a transmission overhaul only to find it was actually corrosion within the electrical supply. You don’t want to end up with a $5,000 mistake on your hands.
All-too-often, the battery becomes the default culprit when an electrical problem occurs. In many cases that may be true. Frequently, an issue can be traced to something as simple as a battery cable or loose connection. Of course, it could also be corrosion in your electrical system. The best way to find out is to complete the necessary diagnostic work.
More than Plug-and-Play
Diagnosing, troubleshooting and working on complex electrical systems is about more than just plug-and-play. You need to be able to understand and troubleshoot errant electronic devices, starters circuits, and batteries. The industry-standard best practice is to use a fault tree. If you see a symptom, you can generally trace it to its root by using an “if this, then this” evaluation.
Common problems technicians run into when troubleshooting electrical systems includes corrosion, parasitic draw, and battery charging problems. Corrosion prevents the electrical system from conducting electricity in the proper manner, which in turn causes resistance. Intermittent flickering of lights or diodes on LED lights are usually because of corrosion.
This is especially true if you are running double or triple trailer configurations. The longer a wire or harnessing solution needs to stretch across a trailer sequence, the greater the chance for a short somewhere in the system. And there are good reasons why electrical systems are so susceptible to corrosion. As an electrical system is powered and unpowered, the wire within it heats up and expands.
When a wire then cools and contracts, it draws in air from around it. If there happens to be moisture in the air or de-icing chemicals, there could be serious corrosion problems. The chemicals used in de-icing solutions are 50% smaller than road salt. They can also pull moisture from dry air, which accelerated the corrosion process.
Fortunately, there are companies out there that make corrosion-resistant electrical system components. Technicians should regularly inspect these components to keep wiring and electrical systems clean and free from damage. Additionally, if you must repair a wire harness or any kind of wiring, make sure to use heat-shrink terminals. Heat-shrink terminals conform to the size and the shape of the wire, which will ensure a permanent seal.
A Tale of Two Batteries
Parasitic draw is a problem in that if the vehicle electronics continue to pull current long after the vehicle is turned off, they could drain the battery down to nothing. If the batteries become too discharged your truck drivers won’t be able to get the vehicle cranked. Even more, batteries that are kept fully charged will not only function better, they will last longer.
The most common mistake a fleet technician or truck driver makes is letting the battery completely discharge without bringing them back to a full state of charge. Trying to start a heavy-duty commercial motor vehicle with a low state of charge or weakened capacity can create a dangerous situation with high amperages and low voltages. The last thing anyone wants to do is overheat the starter motor or even possibly damage the battery cables.
Above all, fleets should prevent batteries from becoming extremely discharged. If they drop to less than 10V, you could be in for some big problems. This can happen when a battery is sitting for an extended period, such as during the holidays, or if the vehicle is currently undergoing unrelated maintenance.
Always remember that your electronics system starts with your batteries. No matter what you do, everything always starts with the battery and battery maintenance. One of the biggest electrical connections at the battery bank. Dirty and corroded terminations generally account for nearly three-fourths of all electrical failures. Always keep batteries and battery terminals clean and keep them fully charged.
Preventative Maintenance is Key
We have talked about a lot of different truck components. If there is one thing that has come from all this, it is that preventative maintenance is extremely important. Are you completing a preventative maintenance program and then benchmarking trucks based on how long they are on the road before required maintenance?
You should have regular reports run in advance and allow trucks to be scheduled at the right intervals. In addition to a full 160-point inspection, you need to keep files on each vehicle, just in case a truck driver notices something, or a technician discovers a problem that otherwise would have remained hidden.
Above all, when it comes to electrical system maintenance, you need to make sure you always sweat the small stuff. Small things matter during electrical system maintenance procedures. Are the connections clean and tight? Is anything corroded or lose? How are your bearings doing? In order to keep your fleet running in prime condition, you’ve got to keep these things in mind.
And though many times we can work ourselves into a hole by completing the wrong troubleshooting steps, if we consult the manuals and don’t stick to methodologies used on far older trucks, then we should be good to go!