The amp meter, or ammeter, on some Harley-Davidson motorcycles gauges the flow of electricity through the motorcycle's electrical system. Unlike a voltmeter, which measures the voltage output produced by the battery and charging system, an amp meter provides a closer look at the actual flow of power both to and from the charging system. Though the constant movement of the amp meter's indicator needle can appear alarming, it is normal and will give you a better idea of your motorcycle's bill of health.
Instructions
1. Sit on the motorcycle and look at the amp meter with the ignition off. The meter's indicator needle should be centered within the display. If the needle is pointing toward the left side of the display, marked as a minus symbol (-) or "Discharge," an electrical accessory is drawing power from the battery.
2. Turn the ignition switch on. The indicator needle will move toward the "Discharge" portion of the meter's display. This occurs because power is being pulled from the battery, creating a negative amperage draw. The amperage draw will increase, depending on the demands of the motorcycle's electrical components and accessories.
3. Start the engine with the transmission in neutral. The indicator needle should move toward the "Charge" portion on the right side of the display. A plus symbol (+) may be used in place of "Charge." This is caused by the addition of a positive amperage output from the motorcycle's alternator, which can provide anywhere from 32 to 45 amps.
4. Rev the engine to 3,000 rpms. The indicator needle will rise slightly as the charging system approaches its peak power output. The amperage reading will drop slightly if you decrease the engine speed below 3,000 rpm but should still remain in the "Charge" portion of the display.
5. Stop the engine and turn off the ignition switch. The indicator needle should return to the center of the display, indicating that there is neither an amperage draw nor a charge.
Tags: indicator needle, amperage draw, charging system, indicator needle should, needle should
