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)

Or, hide this message: temporarily or permanently

Test C

PINPOINT TEST C: THE CHARGING SYSTEM OVERCHARGES (BATTERY VOLTAGE IS GREATER THAN 15.5 VOLTS)


Test C1-C2:






Normal Operation
The generator output is determined by the voltage of the A circuit 35 (OG/LB). The A circuit voltage is compared to a set voltage internal to the regulator and the regulator controls the generator field current to maintain the correct generator output. The set voltage will vary with temperature and is typically higher in cold temperatures and lower in warm temperatures.

Possible Causes
- A circuit 35 (OG/LB) high resistance
- battery ground connections
- generator