Note: The graphics that are illustrated in this section refer to the solenoids that are 24 VDC. Solenoids that are 12 VDC use the same procedure, but only one battery that is 12 VDC is used.
| Required Tools | ||
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| Part Number | Description | Quantity |
| 6V-7070 | Digital Multimeter | 1 |
| 225-8266 | Ammeter Tool Gp | 1 |
| 4C-4911 | Battery Load Tester | 1 |
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| Illustration 1 | g00713118 |
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Basic solenoid circuit |
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A basic four terminal starting motor solenoid circuit is shown in Illustration 1. The two windings that are found in the solenoid are the hold-in winding and the pull-in winding. The windings can be checked with the following procedures.
Hold-in Winding Test
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| Illustration 2 | g00713128 |
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Hold-in winding test |
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- Refer to Illustration 2 in order to make the connections to the solenoid. Disconnect all other leads to the solenoid.
- Close the switch. Observe the reading on the multimeter. Use the battery load tester to adjust the battery voltage until the correct voltage is obtained. Refer to Table 2.
Table 2 Voltage
SpecificationsModel Operating Voltage Measured Voltage 37-MT 12V 12V 37-MT 24V 20V 41-MT 12V 10V 41-MT 24V 20V 42-MT 12V 10V 42-MT 24V 20V
- Observe the reading on the clamp-on ammeter. Refer to Table 3 for the correct amperage.
Note: A high reading indicates a shorted winding. A low reading indicates excessive resistance.
Table 3 Current Specifications Model Operating Voltage Measured Current 37-MT 12V 23±2A 37-MT 24V 6.75A
max41-MT 12V 23.0A 41-MT 24V 14.6A 42-MT 12V 23.0A 42-MT 24V 14.6A
- The hold-in winding can also be checked by measuring the resistance. Disconnect the batteries. Select the “200 Ω” range on the multimeter. Connect one of the leads of the multimeter to the “S” terminal and connect the other lead to the “G” terminal. Refer to Table 4 for the correct resistance reading.
Table 4 Resistance Specifications Model Operating Voltage Measured Resistance 37-MT 12V .50 to .56Ω 37-MT 24V 2.96 to 3.48Ω 41-MT 12V .50 to .59Ω 41-MT 24V 1.37 to 1.77Ω 42-MT 12V .50 to .59Ω 42-MT 24V 1.37 to 1.77Ω
- Replace the solenoid if any of the above readings are incorrect.
Pull-in Winding Test
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| Illustration 3 | g00713129 |
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Pull-in winding test |
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- Refer to Illustration 3 in order to make the connections to the solenoid. Disconnect all other leads to the solenoid.
- Close the switch. Observe the reading on the multimeter. Use the battery load tester in order to adjust the battery voltage. Refer to Table 5 for the correct voltage.
Table 5 Voltage
SpecificationsModel Operating Voltage Measured Voltage 37-MT 12V 12V 37-MT 24V 20V 41-MT 12V 10V 41-MT 24V 20V 42-MT 12V 10V 42-MT 24V 20V
- Observe the reading on the clamp-on ammeter. Refer to Table 6 for the correct current value.
Note: A high reading indicates a shorted winding. A low reading indicates excessive resistance. To avoid excessive heat, do not leave the switch closed for more than 10 seconds at a time. The current will decrease as the heat increases.
Table 6 Current Specifications Model Operating Voltage Measured Current 37-MT 12V 36±2A 37-MT 24V 89±5A 41-MT 12V 56.5±4.5A 41-MT 24V 92.5±7.5A 42-MT 12V 56.5±4.5A 42-MT 24V 92.5±7.5A
- The pull-in winding can also be checked by measuring the resistance. Disconnect the batteries. Select the “200 Ω” range on the multimeter. Connect one of the leads of the multimeter to the “S” terminal and connect the other lead to the “Mtr” terminal. Refer to Table 7 for the correct resistance reading.
Table 7 Resistance Specifications Model Operating Voltage Measured Resistance 37-MT 12V .17 to .19Ω 37-MT 24V .64 to .70Ω 41-MT 12V .11 to .15Ω 41-MT 24V .43 to .49Ω 42-MT 12V .11 to .15Ω 42-MT 24V .43 to .49Ω
- Replace the solenoid if any of the above readings are incorrect.