To check the alternator output voltage, do the following procedures.
Turn off the ignition switch.
Remove the fuel tank (see Fuel System chapter).
Supply fuel to the carburetors with an auxiliary fuel tank.
Disconnect the alternator lead connector [A].
Connect the hand tester as shown in the table 1.
Start the engine, and run it 6,000 rpm 5 minutes.
Run it at the rpm given in the table 1.
Note the voltage readings (total 3 measurements).
Table 1. Alternator output voltage
| Tester Range | Connections | Reading @ 4,000 rpm | |
| Tester (+) to | Tester (-) to | ||
| 250 V AC | One Black lead | Another Black lead | 53.5-72.5 V |
★ If the output voltage shows the value in the table, the alternator operates properly and the regulator/rectifier is damaged. A much lower reading than that given in the table indicates that the alternator is defective.
Check the stator coil resistance as follows.
Stop the engine.
Connect the hand tester as shown in the table 2.
Note the readings (total 3 measurement).
Table 2. Stator coil resistance
| Tester Range | Connections | Reading | |
| Tester (+) to | Tester (-) to | ||
| x 1 Ω | One Black lead | Another Black lead | 0.3-0.4 Ω |
★ If there is more resistance than shown in the table, or no hand tester reading (infinity) for any two leads, the stator has an open lead and must be replaced. Much less than this resistance means the stator is shorted, and must be replaced.
Using the highest resistance range of the hand tester, measure the resistance between each of the black leads and chassis ground.
★ Any hand tester reading less than infinity (∞) indicates a short, necessitating stator replacement.
★ If the stator coils have normal resistance, but the voltage check showed the alternator to be defective; then the rotor magnets have probably weakened, and the rotor must be replaced.
Special Tool - Hand Tester: 57001-1394