Charging System Test

Fig. 6 Voltmeter Test Scale:

All lights and electrical systems in the off position, parking brake applied, transmission in neutral and a charged battery (at least 1.200 specific gravity).
1. Connect the negative lead of the voltmeter to the negative battery cable clamp (not bolt or nut).
2. Connect the positive lead of the voltmeter to the positive battery cable clamp (not bolt or nut).
3. Record the battery voltage reading shown on the voltmeter scale.
4. Connect the red lead of a tachometer to the distributor terminal of the coil and the black tachometer lead to a good ground.
5. Then, start and operate the engine at approximately 1500 RPM. With no other electrical load (foot off brake pedal and car doors closed), the voltmeter reading should increase but not exceed (2 volts) above the first recorded battery voltage reading. The reading should be taken when the voltmeter needles stops moving.
6. With the engine running, turn on the heater and/or air conditioner blower motor to high speed and headlights to high beam.
7. Increase the engine speed to 2000 RPM. The voltmeter should indicate a minimum reading of 0.5 volts above the battery voltage, Fig. 6. If the above tests indicate proper voltage readings, the charging system is operating normally. Proceed to TEST RESULTS if a problem still exists.