ELECTRICAL TROUBLESHOOTING - continued - TM-9-2320-386-24-1-10090

TM 9-2320-386-24-1-1

0012 00

Electrical Troubleshooting (Contd)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

Test 6. Test negative cable 7 voltage drop from batteries to starter motor.

Step 1. Set multimeter to a voltage range that will measure tenths of a volt.

Step 2. Connect multimeter positive lead to terminal stud on end plate of starter motor and

negative lead to frame ground.

Step 3. Crank engine and observe multimeter. A voltage reading exceeding 0.4 volts indicates a

defective starter motor solenoid.

a. Replace starter motor (WP 0091 00).

b. If malfunction still exists, go to tests 7 and 8.

Test 7. Test positive cable 6 voltage drop from batteries to starter motor solenoid.

Step 1. Set multimeter to a voltage range that will measure tenths of a volt.

Step 2. Connect multimeter positive lead to positive terminal post on batteries and negative

lead to starter motor solenoid.

Step 3. Crank engine and observe multimeter. A voltage reading exceeding 0.4 volts indicates a

loose or corroded connection.

Clean and tighten cable connections at batteries, starter, and chassis.

Test 8. Test battery voltage while cranking engine.

Step 1. Set multimeter to a voltage range that will measure 24 Vdc.

Step 2. Connect multimeter directly across battery terminal posts, positive lead to positive post,

and negative lead to negative post.

Step 3. With fuel shutoff switch engaged, crank engine for 15 seconds. Voltage reading should

be 19 Vdc or more during cranking.

a. If battery voltage is not satisfactory, go to malfunction 1 and check battery.

b. If battery voltage is satisfactory, replace starter motor and solenoid assembly

Step 4. Release fuel shutoff switch.

If engine still cranks slowly, notify direct support maintenance.

END OF TESTING!

4. ENGINE CRANKS BUT WILL NOT START

Step 1. Check for defective fuel shutoff solenoid.

a. Turn accessory/battery ON and listen for a "click" indicating fuel solenoid plunger

has opened.

b. If "click" is heard, refer to WP 0009 00, Mechanical Troubleshooting, malfunction 2.

c. If "click" is not heard, go to step 2.

Step 2. Check if plunger is stuck inside fuel solenoid.

a. Tap fuel solenoid lightly.

b. Turn accessory/battery switch OFF, then ON.

c. If "click" is not heard, go to test 1.

d. If "click" is heard, replace fuel shutoff solenoid (WP 0050 00).

Test 1. Check for voltage at fuel shutoff solenoid.