Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Dimmer Switch: Testing and Inspection

1. Disconnect the battery negative terminal.




2. Pull out the rheostat assembly using a (-) driver.
3. Disconnect the connector from the harness.
4. Remove the rheostat assembly.




5. Check for intensity of lamp load. If the light intensity of the lamps changes smoothly without any flickering when the rheostat is turned, the rheostat is normal.