Engine Oil Pressure Sensor

105

TM 9-2320-312-24-2

Testing and Adjusting Section

The solenoid operation also closes the electric

circuit to the motor. Connect one lead of the

multimeter to the terminal connection of the solenoid

that is fastened to the motor. Touch the other lead

to a good ground. Activate the starting solenoid

and look at the multimeter. A reading of the battery

voltage shows that the problem is in the motor. The

motor must be removed for further testing. A zero

reading on the multimeter shows that the solenoid

contacts do not close. This is an indication of the

need for repair to the solenoid or an adjustment to

be made to the pinion clearance for the starting

motor.

Perform a test. Fasten one multimeter lead to the

g00283566

Illustration 93

terminal connection for the small wire at the solenoid

and fasten the other lead to the ground. Look at

6V-7070 Digital Multimeter or the 146-4080 Digital Multimeter

the multimeter and activate the starting solenoid. A

The 6V-7070 Digital Multimeter or the 146-4080

voltage reading shows that the problem is in the

Digital Multimeter is a hand-held service tool with

solenoid. A zero reading indicates that the problem

a digital display, that is completely portable. This

is in the start switch or the wires for the start switch.

multimeter is built with extra protection against

damage in field applications. The multimeter is

Fasten one multimeter lead to the start switch at the

equipped with 7 functions and 29 ranges. The

terminal connection for the wire from the battery.

6V-7070 Digital Multimeter or the 146-4080

Fasten the other lead to a good ground. A zero

Digital Multimeter has an instant ohms indicator.

reading indicates a broken circuit from the battery.

This indicator permits checking continuity for a fast

Make a check of the circuit breaker and wiring. If

inspection of the circuits. The multimeter can also

there is a voltage reading, the problem is in the start

be used for troubleshooting capacitors that have

switch or in the wires for the start switch.

small values.

Starting motors that operate too slowly can have an

Note: Refer to Special Instruction, SEHS7734 for

overload because of too much friction in the engine

complete information for the use of the 6V-7070

that is being started. Slow operation of the starting

Digital Multimeter. Refer to Operation Manual,

motors can also be caused by a short circuit, loose

NEHS0678 for complete information for the use of

connections and/or dirt in the motors.

the 146-4080 Digital Multimeter.

i01854743

Use the multimeter in the DCV range to find starting

system components which do not function.

Engine Oil Pressure Sensor -

Test

Move the start control switch in order to activate the

starting solenoids. The starting solenoid's operation

can be heard as the pinions of the starting motors

SMCS Code: 1924-081

are engaged with the ring gear on the engine

flywheel.

Refer to the Troubleshooting, SENR9819, "PC-42:

Engine Oil Pressure Sensor Open Or Short Circuit

If a solenoid for a starting motor will not operate,

Test" for information on checking the engine oil

it is possible that the current from the battery did

pressure sensor.

not reach the solenoid. Fasten one lead of the

multimeter to the terminal connection for the battery

cable on the solenoid. Touch the other lead to a

good ground. A zero reading indicates that there

is a broken circuit from the battery. More testing is

necessary when there is a voltage reading on the

multimeter.