Component Tests and General Diagnostics

When measuring charging current, never disconnect battery leads with engine running. Avoid applying any mechanical stress where leads extend from the diode holder, do not bend or apply pressure to wire where it is joined to the terminal.
1. Connect a volt/amp meter to system following manufacturers' instructions. Alternator output voltage should be checked between battery positive post and alternator ground.
2. Connect a tachometer to engine, start and run engine until it reaches normal operating temperature.
3. Apply current load to alternator and set engine to run at following speeds:
a. 55 amp alternator, 900 RPM.
b. 65 amp alternator, 950 RPM.
c. 70 amp Motorola alternator, 800 RPM.
d. 70 amp Bosch alternator, 850 RPM.
e. 80 amp alternator, 800 RPM.
4. Compare output readings with those listed in SPECIFICATIONS/ELECTRICAL AND ELECTRONIC SPECIFICATIONS.
5. If output is not within specifications, check drive belt, feed and ground circuits. Repair as required.
6. If wiring and drive belt are satisfactory, repair or replace alternator as necessary.