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April 2006

It’s quite touching to see how protective people are when it comes to their laptop computers. And then there’s the converse when electronically equipped trucks and trailers are subjected to severe welding and jump-start electrical spikes from poorly trained drivers and technicians. Nothing can protect a vehicle from the ultimate spike – a lightning strike. Static electricity discharges flowing from lightning are severe enough to blow all electronic systems in a truck and the only thing left is to make sure that insurance cover is worded to include lightning damage that can run well in excess of R100 000 on today’s heavy trucks. As someone wryly observed – ‘Electronics must work with smoke, ’cause when smoke escapes they stop working’. The world is fast entering the digital age – film cameras are nearly obsolete and the demand for electrically driven automotive components is increasing. Toyota Prius is an example of where we are heading where even air-conditioning is electrically and not engine-powered while most modern trucks, bakkies and cars have ABS brakes. It’s time to be electronically pro-active and not succumb to costly damage and downtime in the way we handle vehicle electronics that are robust but not ‘spike-proof’.

Industry grape-vine news is that just recently a trailer fleet received welding maintenance without isolating ABS systems and blew every ABS module. It’s this type of untrained, ignorant action that breaks down new technology’s usefulness and spreads the perception that electronics doesn’t work in Africa. Ask any fleet about the main factor causing on-road breakdowns and electrical/electronic problems usually rank at the top. 

ESKOM is not helping matters in the Cape, extending as far north as Port Elizabeth, where business is subjected to sudden down-time when power is switched off without warning followed by current surges when power supplies resume. Stand-by power has to be protected against power returning from the national grid otherwise that power generation unit will blow as well. ESKOM power coming into your house is a supposedly perfect AC sine wave and is usually quite close to this. Occasionally it won't be, as lightning strikes and other events impact on electrical power. Such events usually fall into 2 general  categories, namely very high voltage spikes – 1000’s of volts, but usually only a few microseconds in length – or surges of longer duration, but at much lower voltage. So the following definitions are worth noting - 

  • A spike is a transient electrical signal of very short duration and usually high amplitude. Amplitude is the magnitude of change in a varying quantity from its zero value and usually measured in voltage, or decibels to denote volume. 

  • A surge is a sudden, prolonged and possibly damaging, increase in line voltage. Surges can damage electronics and corrupt or destroy data. 

Amateur auto-electrician evils

If there is one serious skills shortage it’s in the auto-electrical field and because trailers are considered ‘lowtech’, trailer wiring harnesses are given amateur-electrical treatment. This has led Nissan Diesel to install a relay box behind the trailer connection that protects their truck tractors against trailer-harness electrical shorts working their way back into the truck tractor electronics. 

Vic Capitani, Senior Manager Engineering Dept, at Nissan Diesel points out that the ‘protection box’ was the result of tracking field problems which, when summarised, showed that there’s nothing wrong with the truck but rather the maintenance standards on trailers. This innovative approach to protecting Nissan Diesel truck tractors was an inhouse engineering development and not an aftermarket device available off the shelf. 

Another amateur electrical evil is cutting into wiring harnesses. According to Frans Schellingerhout, GM South Africa’s Engineer for Isuzu based in Port Elizabeth: "Accessory suppliers cause too many electrical failures through cutting into wiring harnesses. For that reason we fit a standard accessory take-off point mounted behind the steering column right across both the N and F-Series Isuzu truck range." It’s a fact – badly fitted electronic engine protection devices can end up being the cause of more vehicle downtime than they are worth. And usually it’s not the device but the installation cut into a wiring harness that stops the truck. 

OEMs must upgrade batteries and peripherals 

Most truck manufacturers take the cheap option when it comes to 2 X 12V batteries in a 24V-system that are simply strapped to the chassis in an open bracket. In most cases there is no battery cover or method for securing R1200 worth of batteries against casual theft. And because a battery isolator switch is an extra cost, this is also left off the list of useful items that can prevent spikes and damage to electronics. 

The battery position usually needs improvement. Mounted flush against the chassis, it is not easily inspected with a low-mount, flat-deck body. The omission of another add-on cost item, a slider tray, means that batteries are only inspected when there is a crisis. Oh, no – another jump-start! 

One only has to inspect the Volkswagen uppermarket passenger car range to realise the importance that VW places on battery life, connection and security, including the role that this component plays in vehicle electronics. VW cars are a good example for truck manufacturers. 

A pro-active fleet electronic policy

For training and discipline there’s no substitute for a fleet policy to protect valuable vehicle electronics. A few key steps will minimise downtime – 

  • Stop all jump-starting. Invest in standby batteries that stay fully charged. In any event most light vehicle manufacturers forbid jumpstarting. 

  • Ensure that any welding repairs are conducted with electronics in isolation. 

  • Ensure that all accessory installations have full OEM approval and that fitting is documented in detail. • Secure batteries against theft and swap-jacks. 

  • Forbid drivers from conducting their own road-side electrical repairs. However well-meaning a driver may be, casual knowledge is dangerous stuff when it comes to vehicle electrics. 

  • Make it a dismissible offence for anyone who pulls the batteries while the engine is running – it’s deliberate negligence. 

  • Tighten up on trailer electrics. Protect the truck tractor if there is no control over the trailers that will be hitched. 

  • See to it that lightning damage is included in insurance cover. Don’t park trucks where lightning is likely to be attracted. 

  • Train, train and re-train staff so that protecting electronics is a cultural thing – ‘it’s just the way things happen around here.’ 

Here are five key guidelines in avoiding the need for constant jump-starting in a vehicle fleet - 

  1. Maintain the battery. Keep the battery and its connections clean and tight. Keep the electrolyte level up with distilled water.

  2. Do not expect more life from a battery than it is rated to provide. The warranty life of a battery is a good indicator. 

  3. Realize that repeated heavy use of a battery will shorten its productive life. Be careful that the boost starts you give are done correctly. 

  4. Do not use vehicle accessories without the engine running fast enough to replace the electricity used. Using accessories when the engine is not running will drain the battery. Turn off the accessories, such as headlights, before you turn off the engine. 

  5. Be careful when adding aftermarket accessories to your vehicle that you do not overload the capabilities of the battery and charging system output. An alternator or generator can produce only a limited amount of electricity before it is overloaded. 

The terminology grows by which road transport efficiency is judged – telematics, mechatronics, ECU’s, and CANBUS are all terms that form part of daily life. The trouble is that they can all be spiked in one millisecond of ignorance. Avoid the discharge and take charge!

Reference & Acknowledgements: 
NDSU Extension Service, North Dakota State University of Agriculture and Applied Science AE-1021, October 1991 Reviewed and Reprinted, April 1996.