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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No Load Testing


1. Connect Rotunda Digital Volt-Ohmmeter tool No. 105-00051-1 or equivalent to battery terminals according to manufacturers specifications.
2. Record voltage reading, this reading is called base voltage.
3. Start engine, then raise engine speed to 1500 rpm with no electrical loads.
4. Record voltage reading. Voltage reading should be between 14.1-14.7 volts.
5. If voltage reading does not increase 2.5 volts over base voltage with engine operating at 1500 rpm, perform ``Load Test.''
6. If voltage increase is greater than 2.5 volts, repair or replace alternator as necessary.