Paul Messam, Contributor

Seven-year-old Mark Anthony Eaton is given the chequered flag by a marshal to celebrate his first of two wins in the 80cc Baby Class, during last Sunday's go-kart race meet at the Palisadoes International Raceway in Kingston. - Junior Dowie/Staff Photographer

Many motorists might scratch their heads when trying to understand the charging system. Today, Automotives breaks down the details.

The charging system consists of the alternator, regulator and the battery.

"The alternator provides electricity that charges the battery and operates electrical components," explains Keith Austin, an experienced auto electrician with more than 30 years' experience. "The regulator adjusts alternator output to the demand placed on the alternator by electric components."

According to Austin, it prevents excessive electric output, which damages components. It must be noted that in some motor vehicles, the regulator and the alternator are positioned separately.

Other vehicles carry an integrated model, with the regulator housed in the alternator.

Austin says there are four signs which indicate charging problems.

PROBLEM 1: No charge With the engine running, the charging system light glows, or the ammeter registers zero or shows a slight discharge.

PROBLEM 2: Discharge

With the engine running, the charging-system indicator light glows or the ammeter shows a significant discharge.

PROBLEM 3: Undercharged battery

With the engine running, the charging-system indicator light may glow dimly, or the ammeter may show a slight discharge when accessories are on. The headlights will be dim.

PROBLEM 4: Overcharged battery

With the engine running, the ammeter will show a high charge, even with all lights and accessories on. The battery will need water quite often and headlights will be very bright. The bulbs and fuses may burn out frequently.

Testing the alternator and regulator

Step 1: Connect a voltmeter to the battery and make note of the battery voltage with the engine off. If the voltage is less than 9.6 volts, charge battery and take another reading.

Step 2: Start and run the engine at 1,500-2,000 rpm. Record the voltage reading. The reading with the engine running should be two or more volts higher than the battery voltage without the engine running. If it is, the alternator is probably all right. If the voltage is not higher, take note of the servicing procedure below.

To check the regulator, continue to run the engine at 1,500-2,000 rpm until the voltmeter records the highest reading it will reach. If the voltmeter needle continues to climb, the regulator is faulty and should be replaced.

Servicing procedure

1. Check the alternator drive belt for damage.

2. Test the alternator drive belt for proper adjustment.

3. Inspect all connections at the alternator, regulator and battery for tight terminals and cleanliness. Carefully clean corrosion from terminals and see that the wires are not cracked or frayed. Replace damaged wires, which could ground against metal and short the charging system.

4. If the cause of the low-voltage reading has not been determined, the alternator should be replaced or overhauled. To make sure, test the alternator for output. This is done by hooking up a voltmeter and disconnecting the alternator field terminal as the engine is run at fast idle.

If the voltmeter does not read between 14 volts and 15.5 volts, the alternator should be removed from the car for servicing