By Bryan Couch
Motor Coach Industries

On today's motorcoaches, the electrical system powers an incredible variety of equipment, including the new-generation engines and transmissions; overhead reading lights; cooling system blowers, fans and switches; DVD player and other A/V equipment, and much, much more for passenger enjoyment and coach safety.

Yet, it's the coach's hard-charging alternator that's responsible for generating the energy for these amenities and critical components.

While alternators require little maintenance, here are a few tips that can help extend alternator life and reduce chances of coach-down situations.

Check your list
To extend alternator life, trim excessive and unneeded energy expenditures to reduce the load on the alternator. Use the proper light bulbs. Consider the use of LED lighting and contact your MCI Fleet Support Manager to determine the applicable LED lights for your fleet. Keep all electrical connections tight and free of corrosion. That includes the alternator cables and any clamps that secure these cables.

Check bearings and brushes on all electric motors. Torque fasteners. Service the voltage regulator bearings and other serviceable components at recommended intervals (always refer to your service manual). On air-cooled alternators with air intake tubes, check the integrity of the mounting hoses between the tubes and the alternator-never operate the coach with these tubes missing or detached. Check alternator belt tension, even if equipped with a spring tensioner. Too much belt tension not only reduces belt life but it puts unnecessary strain on alternator bearings.

Finally, always remove malfunctioning alternators for testing and repair.

Give drivers the power
Caution your drivers to be aware of electrical requirements while driving. For example, frequent starts and stops don't allow the batteries to recharge. Therefore, the alternator is constantly operating at full capacity, which generates heat. Heat hurts. If this heat is not dissipated, the alternator can be damaged. This is especially a problem with oil-cooled alternators.

In addition, shut off unnecessary loads placed on the alternator. Remind drivers to turn off exterior lights, HVAC and video systems when the coach is being moved around the yard or driven without passengers on board.

Take charge early
Remember to replace alternators before they fail. It's much more cost effective to replace an alternator as part of a routine maintenance program than to service a coach down on the side of the road with passengers.

Don't be complacent
Dual alternators have provided some redundancy in the electrical system. If one alternator fails, the second will allow the coach to continue to a service facility. The down side is that some operators let preventative maintenance slide. With a single-alternator system, more attention is paid to the condition of the alternator, drive belt, tensioner, etc. It's a good idea to continue such vigilance even with two alternators on board.

By practicing preventative maintenance and operating with care, you can help assure that you and your passengers are always "in charge" when it comes to alternator performance.

Bryan Couch is vice president of product development and technical support at MCI.