Troubleshooting

Troubleshooting can be difficult. On the following pages there is a list of possible problems. To make a repair to a problem, make reference to the cause and correction.

This list of problems, causes, and corrections, will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list. Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list can not give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.

1. Contactor Switch (Water Temperature) Will Not Activate Engine Shutoff.

2. Contactor Switch (Water Temperature) Activates Engine Shutoff at Low Temperature.

3. Oil Pressure Switch Will Not Activate Engine Shutoff

4. Safety Instrument Panel Will Not Activate Engine Shutoff.

5. Safety Instrument Panel Stops Engine When Reset Button is Released.

6. Clutch Not Fully Engaged (Slips), Heats, or Lever Moves Out of Engaged Position.

7. End Play for Clutch Shaft is Too Much.

8. Frequency Sensing Relay Prevents Starting Motor Cranking.

Electrical System

NOTE: The starting and charging system components are covered in the BASIC ENGINE SECTION of this manual. The testing and adjusting of the electrical control components (Safety Devices) is covered in the following topics. The examples of testing are typical as related to the earlier electrical set application.

Electrical Safety Devices

Frequency Sensing Relay (Earlier Electric Sets)

Test of the frequency sensing relay (FS) can be made as follows:

1. If the starting motor will operate, proceed to Step 4.

2. If the starting motor will not operate, disconnect lead from "BAT" terminal (3) on relay.

3. Connect a voltmeter from "BAT" lead and to ground, then move Remote, Off, Run switch to "RUN" position.

a. If voltmeter reading is zero, an open exists between this lead and battery.

b. If voltmeter reading is obtained, connect lead to relay "BAT" terminal and proceed.

4. Remove relay cover and observe contacts. When engine is stopped contacts should be closed. Turn adjusting screw (1) clockwise to close contacts.

5. Observe contacts while starting the engine. Allow engine to run at low idle speed.

a. No adjustment is necessary if the contacts remain closed when cranking and open when engine starts. Repeat starting and observation of contacts to insure operation is satisfactory. Stop engine and install the relay cover.

FREQUENCY SENSING RELAY
1. Adjusting screw. 2. "R" terminal. 3. "BAT" terminal.

b. If contacts open during cranking before engine starts, turn relay adjusting screw 1/4turn clockwise and repeat the starting check.

c. If contacts do not open when engine starts, operate at low idle speed and turn adjusting screw counterclockwise until contacts open. Repeat the starting check.

d. If relay contacts cannot be adjusted to open at engine idle, connect a voltmeter from relay "R" terminal (2) to ground and observe reading at low idle.

If reading is approximately half system voltage, replace the frequency sensing relay.

If reading is considerably less than half system voltage, check the "R" terminal wiring for defects.

If relay contacts open at engine low idle but the cranking motor can be energized, check for a grounded lead connected to the relay "BAT" terminal.

Start Slave Relay (Earlier Electric Sets)

The start slave relay (SS) can be checked, in the following manner:

1. Disconnect the lead from larger terminal (2) on the circuit breaker side of the start slave relay.

2. Connect a voltmeter to two small terminals (1) on the relay and move the Remote, Off, Run switch to the "RUN" position. A reading of 11.0 volts or more should be indicated in the 12 volt system.

a. In case of low reading, check the battery and charge it if necessary, be sure all connections in the system are tight. Repair or replace any damaged wiring, and check for proper functioning of components in the circuit. Replace the relay if the required voltage is not obtained.

START SLAVE RELAY
1. Two small terminals. 2. Large terminal.

3. Connect a voltage of at least 11 volts across two small terminals (1) and a voltmeter between large relay terminal (2) on the circuit breaker side and ground. A zero reading indicates the relay should be replaced with a new one. The switch is operating satisfactorily if a voltmeter reading is obtained.

Oil Pressure Sending Unit

The oil pressure sending unit can be checked for resistance calibration to determine if the sending unit or the oil pressure gauge is faulty.

Connect an ohmmeter between the sender mounting fitting (2) and the terminal (1). Connect regulated pressure to the sender and take readings on the ohmmeter at 0 psi (0, kg/cm²), 60 psi (4,22 kg/cm²) and 120 psi (8,44 kg/cm²). Readings should be 227 to 257 ohms, 91 to 114 ohms and 22 to 49 ohms respectively for 2N782 Sending Unit used on Earlier Electric sets.

If the sending unit passes the test replace the oil pressure gauge.

OIL PRESSURE SENDER
1. Terminal. 2. Fitting.

Oil Pressure Switch

The three terminal oil pressure switches (OP) can be checked with a continuity checker across the normally open "NO" (1) and normally closed "NC" (2) contacts. If the switch is working properly, there is never continuity between these two terminals, when pressure is either raising or lowering over a range of 0 to 40 psi (0 to 2,1 kg/cm²) for 2N2916 Switch used on earlier electric sets. Other switches can be similarly tested for proper operation. See the SPECIFICATIONS.

OIL PRESSURE SWITCH
1. Normally open contact terminal. 2. Normally closed contact terminal.

Water Temperature Sending Unit

A resistance check can be made to determine if the gauge or sending unit is faulty if the gauge and a thermometer temperature check disagree. Submerge the sending unit bulb (3) in a pan of heated water. The ohmmeter reading taken between the bushing nut (2) and the terminal (1) should be as listed in the SPECIFICATIONS. If the sending unit passes the test the gauge is faulty.

WATER TEMPERATURE SENDING UNIT
1. Terminal. 2 Bushing nut. 3. Bulb.

Water Temperature Contactor Switch

Fabricated heat sink.2F112 Thermometer.3J5389 Plug.

1. Fabricate a heat sink as illustrated. Material can be brass, steel, or cast iron. Drill a 23/32 in. hole through the heat sink and tap for 1/2 in. NPT.

2. Mark wiring connections to contactor terminals and disconnect wiring. "C" and "NO" terminals are normally used.

3. Remove the contactor and plug the opening with 3J5389 Plug. Install the contactor in the heat sink.

4. Reconnect the contactor to the wiring to check the entire system; contactor, wiring and shutoff solenoid.

HEAT SINK FOR TESTING [Dimensions in inches (mm)]

NOTE: If this cannot be done, use an ohmmeter or continuity tester across the contactor terminals to check the setting.

5. If the contactor is reconnected, start the engine and run it at low idle. The fuel pressure switch will complete the circuit to the shutoff solenoid.

TESTING CONTACTOR
1. 2F7112 Thermometer. 2. Fabricated heat sink.

6. Immerse heat sink and sensing element in water. Heat the water, and, by using an accurate thermometer, note the temperature at which engine shuts down (or continuity is indicated). Allow water to cool. The contactor will reset automatically when the temperature lowers approximately 12° F (8° C) from the shutdown temperature. See SPECIFICATIONS for contactor being tested.

7. Install new contactor if necessary.

NOTE: To test the system beyond the contactor, a jumper can be touched between the "C" and "NO" contactor terminals to simulate contactor operation.

Alternate Method of Checking Water Temperature Contactors

1. Disconnect the wires from the contactor.

2. Connect ohmmeter or continuity tester across the contactors.

3. Start the engine and cause it to overheat by reducing coolant flow or air flow through radiator. Do not exceed the maximum temperature by more than 3°.

4. Observe ohmmeter or continuity tester to see when the contactor shows continuity. The temperature at which this occurs is shown in the SPECIFICATIONS for contactor being tested.

5. Allow engine to cool and then stop engine.

6. Install new contactor if required and connect wires to water temperature contactor.

Enclosed Clutches

Clutch Adjustment

The clutch engagement lever pull adjustment establishes the clutch plate pressure. The proper clutch lever pull is indicated in the chart.

The clutches use two types of adjustment lock pins. Pin (1) should be pushed in and the adjusting ring rotated. Pin (2) should be pulled out and the ring rotated to adjust the clutch.

CLUTCH ADJUSTMENT
1. Lock pin (push in type to unlock). 2. Lock pin (pull out type to unlock).

Assembly Adjustments

Tighten hub nut to torque of 30 lb. ft. (4,1 mkg) to remove all clearance between parts, then tighten additional amount as shown in chart.

Clutch Shaft Seal Wear Sleeve Installation

Clutches which have oil lubricated shaft bearings are equipped with oil seal wear sleeves (2) on the shaft. Install wear sleeves with guide assembly (1) part of 1P2410 Wear Sleeve Installation Tool Group. Be sure the sleeve contours blend in with the shoulder fillets (3) on the shaft.

WEAR SLEEVE INSTALLATION
1. Guide assembly. 2. Wear sleeve. 3. Shaft shoulder fillets.

Shaft Bearing End Clearance

Where shim adjustment is used, tighten the retainer without shims until shaft turns with dry bearings at torque of 60 lb. in. (70,0 cm.kg) in addition to seal drag. Measure the space between the retainer and carrier and add .013 in. (0,33 mm) to this measurement. Remove the retainer, then install shims and retainer and cap screws with locks. Drive the front bearing cup to the front by striking the output end of the shaft with a soft hammer. The end play should now be .004 to .007 in. (0,10 to 0,18 mm).

Clutch and Mounting Adjustment Check

At time of installation, check the flywheel and flywheel housing face and bore run out.

After clutch installation, check clutch shaft end play. End play should be .004 to .007 in. (0,10 to 0,18 mm) after installation. Check crankshaft end play after clutch installation to be sure end play exists within the limits as specified in the ENGINE SPECIFICATIONS SECTION of this manual.