Pin Point Test M: The Charging System Warning Indicator Is Never On

WARNING: This page is about a different car, the 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

M1 CHECK THE CHARGING SYSTEM WARNING INDICATOR OPERATION
- Key in OFF position.
- Disconnect: Generator C102a (gasoline and diesel engines with a single generator).
- Disconnect: Powertrain Control Module (PCM) C1381a (diesel engines with dual generators).
- For vehicles with gasoline and diesel engines equipped with a single generator, connect a fused (10A) jumper wire between the generator C102a-1, circuit 904 (LG/RD), harness side and ground.
  
  Fig 1: Checking Charging System Warning Indicator Operation (1 Of 2)
  Courtesy of FORD MOTOR CO.
- On diesel engines equipped with dual generators, connect a fused (10A) jumper wire between the PCM C1381a-30, circuit 3090 (VT), harness side and ground.
  
  Fig 2: Checking Charging System Warning Indicator Operation (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Key in ON position.
- Does the charging system warning indicator illuminate?
Yes : On gasoline and diesel engines with a single generator, INSTALL a new generator. REFER to GENERATOR AND REGULATOR . TEST the system for normal operation.

On diesel engines equipped with dual generators, GO to M5.

No : For gasoline and diesel engines equipped with a single generator, REMOVE the jumper wire. GO to M3.

For diesel engines equipped with dual generators, REMOVE the jumper wire. GO to M2.
M2 CHECK CIRCUIT 904 (LG/RD) FOR AN OPEN
- Key in OFF position.
- Disconnect: Instrument Cluster C220a.
- Measure the resistance between the instrument cluster C220a-15, circuit 904 (LG/RD), harness side and the PCM C1381a-30, circuit 3090 (VT), harness side.
  
  Fig 3: Checking Circuit 904 (LG/RD) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to M5.

No : REPAIR the circuit. TEST the system for normal operation.
M3 CHECK CIRCUIT 904 (LG/RD) FOR AN OPEN
- Key in OFF position.
- Disconnect: Instrument Cluster C220a.
- Measure the resistance between the instrument cluster C220a-15, circuit 904 (LG/RD), harness side and the generator C102a-1, circuit 904 (LG/RD), harness side.
  
  Fig 4: Checking Circuit 904 (LG/RD) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to M4.

No : REPAIR the circuit. TEST the system for normal operation.
M4 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect all the instrument cluster connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the instrument cluster connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes : INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER . TEST the system for normal operation.

No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
M5 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - GASOLINE ENGINES (gasoline engines), ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE (diesel engines). TEST the system for normal operation.

No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.