Testing the alternator and checking that the alternator brushes are working properly is the recommended action.
- 1/4" Nut Driver or Wrench
- Begin by disconnecting the brown wire from the Field terminal of the alternator and the white wire from the B+ or POS terminal of the alternator.
- The wiring sticker should help you to identify the designated terminals.
- A jumper wire is needed to proceed with this test. (A jumper wire can be fashioned from wire with slip-on connectors crimped to each end or the jumper can be a normal piece of wire with the coating stripped from each end. The designated terminals have a small hole that the stripped end of the wire can be threaded through to create the jumper.)
- Connect one end of the jumper wire to the B+ or POS terminal and the other end to the Field terminal.
- Step on the unit for about 10-15 seconds to verify resistance.
- If no resistance between the B+ or POS and Field, this normally indicates that the alternator brushes are worn or damaged.
- Remove the jumper wire and then remove the alternator brushes for further inspection.
- Using the 1/4" driver or wrench, remove the two bolts from the brush cover.
- Once the bolts are removed, pull on the Field terminal to remove the alternator brushes.
- Inspect the alternator brushes.
- The brushes should be smooth and free of cracks, nicks, and breaks.
- The brushes are spring-loaded; Confirm when pressed that the brush will spring back to position.
- Replace the brushes if necessary.
- When re-installing the alternator brushes to the alternator, the brushes will face down toward the inside of the alternator. (Due to the brushes being spring-loaded, it may be necessary to press the brush into its housing for ease of installation and to avoid damaging the brush.)
- Test the unit after replacing the alternator brushes.
- Reconnect the jumper wire to the B+ or POS terminal and the Field terminal.
- Step onto the unit and verify resistance.
- In this example, the alternator brush replacement was all that was necessary to correct the resistance problem.
- With resistance verified, it is time to remove the jumper wire and reconnect the white wire to the B+ or POS terminal and the brown wire to the Field terminal.
- Make sure all cables are connected (including the console cable) and this completes the alternator test.