Generator Functional Test (1987 & 1988)
NOTE:
The following applies to steps on the generator functional check chart. See Fig 1
.
- At key on, engine off, volts telltale should be on.
- If volts telltale is on with engine running, diagnose by performing volts telltale check. See VOLTS TELLTALE CHECK .
- Always diagnose codes B410, B411 and B412 before performing generator functional test. See SELF-DIAGNOSTIC SYSTEM . Those trouble code charts will check BCMs ability to detect generator faults and to control generator operation.
- This step checks for generator overcharging the battery. Generator overcharging the battery may be accompanied by code B412 (either current or history) and battery volts high message on Driver Information Center. Code B410 accompanied by "Service Electrical System" message may also set. Visual signs of battery overcharge may include battery electrolyte leakage from battery vent tubes, low electrolyte level indicated a Yellow battery eye or low electrolyte levels seen through the side of battery case.
- This step checks for proper generator current output. Generator output below 80 amps at 1500 RPM may result in undercharging of battery. Generator undercharging battery may be accompanied by current or history code B411 and "Battery Volts Low" message on Driver Information Center. Code B410 accompanied by "Service Electrical System"