Introduction

When the words "use again" are in the description, the specification given can be used to determine if a part can be used again. If the part is equal to or within the specification given, use the part again.

When the word "permissible" is in the description, the specification given is the "maximum or minimum" tolerance permitted before adjustment, repair and/or new parts are needed.

A comparison can be made between the measurements of a worn part and the specifications of a new part to find the amount of wear. A part that is worn can be safe to use if an estimate of the remainder of its service life is good. If a short service life is expected, replace the part.

Reference: See 3208 Marine Engine Attachments, SENR2133, for Specifications

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 given 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 For Water Temperature Fails To Activate Alarm.

2. Contactor Switch For Water Temperature Activates Alarm At Wrong Temperature.

3. Switch For Oil Pressure Fails To Activate Alarm.

4. Electrical Indicators Give Wrong Readings.

Problem 1: Contactor Switch For Water Temperature Fails To Activate Alarm

Probable Cause:

1. Alarm circuit toggle switch (if equipped) is in the OFF position.

Place alarm circuit toggle switch in the proper position.

2. Low Water Level In Cooling System:

Fill the cooling system.

3. Wrong Setting Of Switch:

Make a test of temperature setting and, if necessary, install new contactor switch with correct setting. See Specifications.

Problem 2: Contactor Switch For Water Temperature Activates Alarm At Wrong Temperature

Probable Cause:

1. Wrong Setting Of Switch:

Make a test of temperature setting and, if necessary, install new contactor switch with correct setting. See Specifications.

Problem 3: Switch For Oil Pressure Fails To Activate Alarm

Probable Cause:

1. Alarm circuit toggle switch (if equipped) is in the OFF position.

Place alarm circuit toggle switch in the proper position.

2. Wrong Setting Of Switch:

Test and replace switch if necessary.

Problem 4: Electrical Indicators Give Wrong Readings

Probable Cause:

1. Wrong Connections:

Check wiring connections to be sure they are tight. Check to see that the indicators are correctly connected as shown in the wiring diagrams.

2. Sending Units Fail To Operate:

Check the sending units and install new sending units if necessary.

3. Wrong Sending Unit In System:

Install correct sending unit.

Electrical System

Water Temperature Switch

First Method Of Checking

1. Make a heat sink as shown. Material can be brass, steel or cast iron. Drill a 17.8 mm (.70 in) hole through the plate and use a tap to make 1/2 in NPT threads.

2. Put marks on wire connections to water temperature switch terminals and disconnect the wire.

Heat Sink [Dimensions in mm (in)]

Test Of Water Temperature Switch
(1) 2F7112 Thermometer. (2) Fabricated heat sink.

3. Remove the water temperature switch and install a 3J5389 Plug. Install the water temperature switch in the heat sink.

4. Connect the wires to the water temperature switch to check all of the system; water temperature switch, wires, etc.

NOTE: If the water temperature switch cannot be removed, use the second method of testing.

5. When the water temperature switch is connected, start the engine and run it at low idle rpm. The oil pressure switch will complete the circuit when the engine is running.

NOTE: When applying heat to the water in Step 6, be sure to stir (keep water moving) while heating.

6. Put the heat sink and contactor element in water. Use blocks to support the heat sink at surface level. Use a torch to make the water hot and read the temperature on thermometer (1) at which the water temperature switch is closed. Check the specifications for the respective temperatures at which the water temperature switch opens and closes. Let the water temperature go down. The contactor switch will open when the temperature is 8°C (12°F) lower than the temperature at which the contactor closes.

7. Install new water temperature switch if necessary.

To check other components in the system, put a jumper wire between C and NO terminals of the water temperature switch.

Second Method Of Checking

1. Remove the wires from the water temperature switch.

2. Connect the 8T0500 Circuit Tester between the C and NO terminals.

3. Look at the circuit tester to see when the water temperature switch closes. The light will be activated. Check the specification for the water temperature switch closings.

4. Start the engine and get it hot. Temperature must not go more than approximately 3°C (37°F) above switch activation temperature.

5. Let the engine run at a reduced speed to lower the coolant temperature before stopping the engine.

6. Install new water temperature switch if needed.

Electrical Indicators And Sending Units

Remember that the electrical indicators and sending units are to operate in electrical balance. For this reason, the voltage and resistance ratings are important to get the correct indications on the indicators.

Sending Units For Oil Pressure

Sending Unit For Oil Pressure
(1) Terminal. (2) Fitting.

The sending unit for engine oil pressure can be checked for resistance to find if it is operating correctly. Connect the sending unit to a pressure source that can be measured with accuracy. Connect the ohmmeter between fitting (2) and terminal (1). Take resistance readings at the pressures given in the Attachment Specifications section.

If the test performance is correct for the sending unit for the oil pressure, install a new indicator.

Sending Unit For Water Temperature

Sending Unit For Water Temperature
(1) Bulb. (2) Nut. (3) Connection.

1. Connect a multimeter between terminal (3) and nut (2). Put bulb (1) in heat sink then into a pan of water. Do not let the bulb have contact with the pan (see water temperature switch for more detail).

2. Put a 2F7112 Thermometer in the water to measure the temperature.

3. Refer to Sending Units For Water Temperature in the Specifications section. Take resistance readings at the temperature shown.

4. If a unit does not have the correct resistance readings, replace the unit.

Magnetic Pickup

(1) Distance between end of magnetic pickup and gear. (2) Nut.

(1) Distance between end of magnetic pickup and gear ... 0.30 to 0.75 mm (.012 to .030 in)

NOTE: This distance is set by turning magnetic pickup into threads until magnet is against the gear tooth while the engine is stopped. Now back magnetic pickup out 1/3 ± 1/10 turn and tighten nut as follows.

(2) Nut. Tighten nut to a torque of ... 45 ± 7 N·m (33 ± 5 lb ft)

Tachometers

Tachometers can be adjusted by the following procedure.

1. Remove the plastic plug on the rear of the tachometer.

2. Using a small screw driver, turn the adjusting screw to increase or decrease the tachometer reading.

3. Replace the plastic cap.

Electric Indicators

Wiring Diagram For Test
(1) System voltage. (2) Sender resistance. (3) Case ground.

Prior to inspection of individual pointer positions warm up indicator for minimum of five minutes. Using each sender resistance from the calibration supplied in the Specifications manual and the proper system voltage, each indicator can be checked. Check calibration indicator with ascending pointer. Position of pointer with current off is immaterial. The test must be made when the indicator is installed at the angle of 30 degrees back from vertical position.