MBE 900 DDEC VI Troubleshooting – Section 5.6 Defective Starter

Section 5.6
Defective Starter

To determine if a defective starter is causing starting difficulty, perform the following steps:‪

1. Place the red lead of a voltmeter to the solenoid “BAT” terminal; see Figure "Starting Motor Available Voltage Test" .
   

   1. Black Voltmeter Lead‪	4. Harness Tube‪
   2. Starter Ground Terminal Lug‪	5. Volt Ohm Meter‪
   3. Red Voltmeter Lead‪

   Figure 1. Starting Motor Available Voltage Test

2. Place the black voltmeter lead to the starter ground terminal; see Figure "Basic Cranking Circuit" .
3. Engage the starter switch.
4. View the voltage reading on the meter.
   1. If the voltage is less than specification while cranking the engine, replacement is necessary; refer to "5.6.1 Starter Replacement" .
   2. If the voltage is to specification while cranking the engine, check the cranking speed; refer to "5.7 Low Cranking Speed" .

Section 5.6.1
Starter Replacement

Perform the following steps for starter replacement:‪

1. Replace the starter, refer to them MBE90 service manual, electrical equipment chapter.
2. Verify replacement of starter; refer to "5.6.1.1 Test Engine with Replaced Starter" .

Section 5.6.1.1
Test Engine with Replaced Starter

To determine if the replaced starter resolved starting difficulty, perform the following steps:‪

PERSONAL INJURY ‪
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.‪

1. Attempt to start and run the engine, if the engine starts and runs, no further troubleshooting is required. Shut down the engine.
2. If the engine fails to start and run, check the cranking speed; refer to "5.7 Low Cranking Speed" .