No Resistance When Stepping; No Resistance And No Field Light - Stairmaster 8G Gauntlet Service Manual

No Resistance When Stepping

1. Check alternator brush length.
a. Remove user-right side cover
b. Remove brown wire from W3 (FLD BRN) post of alternator.
c. Loosen ¼" bolts on W3 post.
d. Remove and verify brush length and quality. We recommend replacing brushes that are ¼" or less.
2. Remove the right side panel to view the three LED's on the lower PCB board.
3. Begin moving the staircase.
4. If all three of the red LEDs on the relay board are illuminated but there is no resistance, replace the alternator
brushes (SM24557) if worn or the alternator (SM22900).

No Resistance and No Field Light

Use these instructions if you can freewheel the staircase and the field LED does not light on the relay board while the
staircase is moving.
1. Perform tach test by entering diagnostics on the console.
2. If there is no tach signal sensed on console
a. Check for 0.6 to 0.7 volts AC at the W‐4 (Tach) terminal of the alternator.
b. If no voltage, remove the blue tach wire from the alternator, while staircase is moving.
iii.
iv.
1. If the voltage checks good, remove the blue connector from the W‐4 (Tach) terminal of the alternator. Lightly
scrape the connector and re‐install. Re‐check.
2. If still bad, replace the console.
Good Alternator Brush Length ( >0.25")
Touch the tach wire to the field terminal.
If the field LED lights, replace the alternator.
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