Rotor Open Or Short Circuit Test
- Remove rotor from alternator. Set ohmmeter on "x1" scale. Contact each probe to rotor slip ring. Reading should be 2.3-2.5 ohms. A higher resistance reading indicates damaged slip ring solder connection or broken wire.
- A lower reading indicates a shorted wire or slip ring. Replace rotor if damaged. Contact one ohmmeter probe to slip ring and other probe to rotor shaft.
- Ohmmeter reading should be infinity. A reading other than infinity indicates rotor is shorted to shaft and must be replaced. Damaged slip ring terminals or solder touching rotor shaft will cause shorted condition.
ALTERNATOR SPECIFICATIONS
| Application | In. (mm) | |
|---|---|---|
| Brush Length | ||
| New | .48 (12.2) | |
| Wear Limit | .25 (6.4) | |
| Slip Rings | ||
| Maximum Runout | .0005 (.013) | |
| Minimum Diameter | 1.2 (31) | |