Alternator not Charging
electrical
Description
The unit was running and alternator current flow stayed below -1.0 amps for three continuous minutes, and the unit gives alarm only or shutdown and alarm if configured.
Activation Conditions
Unit is running and the current flow is less than -1.0 amps (discharge) between the alternator and the battery for three continuous minutes.
Unit Behavior
Alarm only, or if Alternator Check Shutdown Configuration is set to “YES” shutdown and alarm.
Reset Conditions
Auto reset (if not shutdown) when alternator is charging or alarm may be manually reset using the display mounted keys or by turning the unit off, then back on again.
Corrective Actions
1. Check Water Pump/Alternator Belt Tension and Condition: Verify no glazing, cracking, or slipping. Refer to Section Figure 1.15 . Replace if required. 2. Check Current Transformer (CT) a. Check current value. Power up control system in PC mode. (Refer to Section 1.3.2.) Check Unit Data. Must be -2.0 to 1.5A with no load. b. Check CT power from main microprocessor. Must have +5 VDC from terminal 2MM-29 to PCM-31. c. Check CT ground to main microprocessor. Check wiring from terminal 2MM-23 to PCM-30. d. Check CT signal to main microprocessor. Check wiring from terminal 2MM-12 to PCM-29. 3. Check Alternator Wiring and Output a. Check output and ground wiring (with unit OFF). Ground from alternator G terminal to PCM-T2. Positive from alternator B+ terminal to PCM-T3. b. Check output (with unit running). When the unit is started, voltage at the battery will begin near 12.0 VDC, and slowly rise toward 13.5 VDC as the battery charges. 4. Check for Add-on Equipment Drawing Too Much Current: Check amperage of added-on components and accessories. Total current draw including the actual unit current draw and all add-on components and accessories must be less than alternator rating. 5. Perform Pretrip Check: Clear Active Alarm list, then run Pretrip and check for any new alarms. Any active alarms must be corrected and cleared before proceeding.