Bench Testing: Rotor: Bosch
- Place DVOM on lowest scale. Connect DVOM across slip rings. Ensure resistance is within specification. See ROTOR RESISTANCE table.
- If resistance is too low, rotor has short circuit and must be replaced. If resistance is infinite (no continuity), rotor has an open circuit and must be replaced.
- Place DVOM on x1000 scale. Connect DVOM between rotor core and either slip ring. Continuity should not exist. If continuity exists, rotor is grounded and must be replaced.
- Measure slip rings for wear and eccentricity. If wear is visible, turn rotor on lathe and polish slip rings. Maximum runout for slip rings is 0.11" (0.03 mm).
ROTOR RESISTANCE
| Application | Resistance (Ohms) | |
|---|---|---|
| Bosch | ||
| 65-Amp Generator | 3.2-3.6 | |
| 80-Amp Generator | 2.6-3.2 | |
| 90-Amp Generator | 2.7-3.2 | |
| 115-Amp Generator | 2.4-2.8 | |
| 140-Amp Generator | 2.4-2.8 | |
| Motorola | ||
| 65-Amp Generator | 3.5-4.5 | |
| 80-Amp Generator | 3.5-4.5 | |