The 10 biggest mistakes made in electrical designs

OEMs can no longer afford to look upon this important area as an afterthought

Story by Gary L. Gustafson, Nov. 22, 2006

Electrical systems have historically been treated as many things by powersports manufacturers—a red-headed step-child, an elephant in the corner or even an afterthought. This is changing. In the 21st century, the one thing OEMs cannot afford to do is treat electrical systems as unimportant, and those that don’t will have a competitive advantage.

The following are some of the most common mistakes powersports companies make with their electronics development.

1. Insufficient charging system power.

This will result in dead batteries, dim headlights, poor accessory performance, perplexed dealer technicians and most significantly, dissatisfied customers. On the other hand, a maximized charging system can be the foundation for game-changing innovation. For example, the electric-assist power steering system available on 2007 Yamaha Grizzly 700 FIs required a 200 watt upgrade to their stator. ATV OEMs which do not have a surplus of electrical power available will have to deal with this inadequacy first if they decide to release their own electrical power steering systems.
It is always easiest to specify a high-output magneto charging system when a new engine platform is designed. Sufficient room must be allowed in the crankcase casting for the stator and flywheel, and provisions for cooling the stator may also need to be made. While it is sometimes possible to upgrade an existing magneto-based charging system, the cost versus return is substantially less favorable than just designing it with a surplus of power to being with. I always pushed for higher charging system outputs at the major OEMs I worked for when a new engine was being designed. In all cases, there was a need for the extra power discovered before the models even went to production. In addition, with the explosion in aftermarket accessories extra charging power will be demanded regardless of if the production electrical system needs it or not. The bottom line is that no customer ever complains about having too much electrical power, but they will definitely complain if there is not enough.

2. Not allocating the electrical system design team resources equivalent to that of the mechanical design teams.

Powersports OEMS, by and large, have staffs who are 99% mechanical in their expertise. Yet, if all of the electrical components on the vehicle from ignition coils to the taillight are added together, the per cent of vehicle cost that is electrical is closer to 10%, meaning 1% of the staff is responsible for 10% of the content. Many aftermarket companies do not have one person with electrical engineering training on their entire staff. The quality and breadth of powersports electrical designs has lagged due to this design imbalance.

In today’s powersports business model, every manufacturer is in a rush to have a little more suspension travel, more horsepower, a better chassis and other features. A paradigm shift is needed. Devoting more resources to electrical development offers an enormous opportunity for more satisfied customers, cost reductions, warranty reductions and product differentiation. The next great powersports technology revolution will have more to do with electrical than mechanical design, and the first company to embrace this strategy will benefit tremendously. Many industries are littered with the shells of once-great brands which were overcome by technology revolutions that relegated them to the ash heap of history. It is only logical that such technology revolutions allow the potential for small ‘David’-type companies to set the ‘Goliaths’ of the powersports world on their head. It is a good bet that electronic or mechatronic technologies will be at the heart of the coming sea-change.

3. Not planning for hose, wire and cable routes.

Poor wire, hose and cable routes can cause very expensive problems. Studies conducted for powersports manufacturers reveal annual warranty costs upwards of hundreds of thousands of dollars per year due to overlooking this detail. Product safety recalls can also be triggered by these problems and the resultant lawsuits have the potential to cause a smaller manufacturer to close their doors. 

One good example of this is throttle cable routing. Throttle cables have not changed in many years. The same goes with how they are routed—being ‘zip-tied’ to the bars on many handlebar-steered vehicles. As every service technician can attest, improperly installed throttle cables can cause problems ranging from engine stalls to serious safety issues. However, very little progress has been made in controlling their placement.

Unfortunately, hose, wire and cable routing problems are an inherent result of the design process at most OEMs. Manufacturers usually do not design routes for hoses, wires and cables concurrent to the rest of the vehicle model. Instead, they lay out the vehicle and then make a last-minute demand for their electrical gurus to find a place for the wiring to go. I was disappointed, but not surprised, to see a friend’s brand new ATV have wires hanging down inside a fender, very vulnerable to being torn off. And this quad was from a company with a reputation for rock-solid reliability. The tragedy is, these types of problems are completely avoidable with some common sense and design process control.

4. Not designing for serviceability.

As much as 60% of all electrical warranty is due to misdiagnosis. This problem is another offshoot of manufacturer tendencies to address electrical designs at the tail end of the vehicle design cycle. This approach does not allow electrical engineering staff time to develop useful electrical troubleshooting procedures for service manual creation.

Common serviceability problems include out of date schematic diagrams, worthless troubleshooting flowcharts and meaningless or non-existent diagnostic blink codes. In addition, electrical connections are often hard to access for service. If it takes a long time for a service technician to get at a part for testing, he is almost certainly going to replace it regardless.
Manufacturers should adhere to a few basic rules for electrical-system serviceability. Some of them include: Centralize components into an electrical center, but avoid placing electrically noisy items next to low-current signals. Specify light bulbs that are off-the-shelf if possible, keep schematic diagrams up-to-date, and locate electrical connections where they can be reached with minimal labor time. If new electrical features are added, have all supporting technical information available for dealers from the moment the product is released. Develop an iron-clad specification for wire color functions. Continuity in wire color functions will help technicians to grow their familiarity with evolving electrical systems. Use two functions per wire color if the vehicle has EFI, one function dedicated to the engine electronics and one dedicated to the chassis electronics. Carbureted vehicles should only need one function per wire color. Another best practice is to have company development technicians and engineers maintain a database of problems they encountered during production, along with how they solved them. This database can be tapped to develop the entire service manual, not just the electrical section. Add diagnostic capability to components that have advanced microprocessors and large amounts of I/O such as speedometers. Diagnostic capability is often available for free by simply adding a little more software programming into these components.

One rule to always keep in mind—assume that the people who will be servicing the vehicle have no electrical training. Because of this fact, electrical system design-for-serviceability must be emphasized all the more.

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