Caterpillar SR4B — Winding Resistance Measurement
Testing & diagnosis · Windings
For the Caterpillar SR4B, from the Caterpillar service manual.
Applies to: Caterpillar SR4B
Before you start
- Temperature affects resistance; test at room temperature only
- Winding damage if outside specifications
Procedure
- Disconnect winding from other components before measuring
- Measure armature windings with milliohmmeter (L2, L4, L5)
- Measure field windings with multimeter (L1, L3)
- Test at room temperature only
- Compare measurements to specification values
- Verify no continuity between windings or between winding and ground
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- L2 < 0.1 ohm
- L4 < 0.1 ohm
- L5 < 0.1 ohm
- L1 3-6 ohm
- L3 0.75-2.0 ohm
Full service-parts list: Caterpillar SR4B →
Source: Caterpillar service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.