B. Test Procedure Using Sun Volt Ampere Tester

(VAT-40 or equivalent):

i) Circuit Resistance Test:

1. Set TEST SELECTOR knob to # 2 CHARGING position.

2. Set LOAD INCREASE knob to the OFF position.

3. Set VOLT SELECTOR knob to the EXT 18 V position.








4. Connect tester leads as shown in the figures.

5. Start the engine and increase to 2000 RPM.

6. Adjust LOAD INCREASE knob until the reading of the Red Ammeter Scale indicates 175 A.

7. Observe the reading on the Green Voltmeter Scale. Note this reading.

8. Set VOLT SELECTOR knob to INT 18 V position. Observe the reading on the Green Voltmeter Scale. Subtract this reading from the reading obtained in step 7. The difference is the voltage drop caused by circuit resistance and must be less than 0.5 volts.

NOTE:
If the voltage drop exceeds 0.5 volts, then conduct the test on the following page (Insulated Circuit Resistance Test).

ii) Insulated Circuit Resistance Test:

NOTE:
Leave main clamps on VAT-40.





1. Connect test leads as shown.

2. Set VOLT SELECTOR knob to EXT 3 V position.

3. Start the engine and adjust speed to approximately 2000 RPM.

4. Adjust LOAD INCREASE knob until Red Ammeter Scale indicates 175 A.

5. Observe voltage reading on Black (3 Volt) Voltmeter:

*If below 0.5 volts, proceed to the "Ground Circuit Resistance Test".

*If above 0.5 volts, repeat this test with voltmeter connected across each connection and each wire of the insulated circuit to isolate the point of high resistance.

iii) Ground Circuit Resistance Test:





1. Connect test leads as shown.

2. Start the engine and adjust speed to 2000 RPM.

3. Adjust LOAD INCREASE knob until Red Ammeter Scale indicates 175 A.

4. Observe Black (3 volt) Voltmeter Scale. Test with voltmeter leads connected across each connection and each wire of the ground circuit to isolate the point of high resistance.