VOLTAGE | AMPS | LIKELY CAUSE |
Below 9.6 | High | Bad starter or a very hot or |
|
| cold engine |
Below 9.6 | Low | Bad Battery or Loose Battery |
|
| Terminals |
Above 9.6 | Low | Bad Connections at Starter or |
|
| Solenoid |
INSULATED-POS CIRCUIT TEST
1.Set the Volts Selector to “External” (±199.9V. scale)
2.Connect Volt test leads as shows in the following (Figure 3). Clip from battery POS (+) post to the input terminal on the starter motor.
BLACK
STARTER
-POS +
BATTERY
CHASSIS
SOLENOID RELAY
Figure 3
Connections For INSULATED-POS CIRCUIT TEST
1.Disable ignition (as described earlier) to prevent engine from starting during test.
2.Operate starter and read voltmeter while cranking.
3.Test Conclusion: Good circuits drop less than 0.4 volt on a 6 volt system and less than 0.5 volt on 12 volt systems. If okay, go to the Ground Circuit Test. If an excessive voltage drop is detected, further isolate the problem by retesting across the individual circuit components.
12 VOLT CRANKING CIRCUIT
TYPICAL VOLTAGE DROP MAXIMUMS
Each Cable | 0.2 | volt |
Each connection | 0.1 | volt |
Solenoid Switch | 0.3 | volt |
GROUND-NEG CIRCUIT TEST
Trouble can be caused by a poor ground connection, a loosed starter motor mounting bolt, a bad battery terminal post connec- tor, or a damaged cable from battery to engine block.
1.Select External Volts (±199.9V display)
2.Connect Volt test leads to battery NEG
| RED |
BLACK | STARTER |
- NEG | + |
BATTERY |
|
CHASSIS
Figure 4
Connection For GROUND-NEG CIRCUIT TEST
3.With ignition disabled, crank engine and watch voltmeter to see that reading is not too high.
4.Test Conclusion: A good circuit will typically have less than 0.2 volt drop. If okay, go to Solenoid Control Switch Test, but if not, isolate the cause of excess voltage drop by testing across each circuit part.
SOLENOID CONTROL SWITCH TEST
1.Selection External ±199.9V display
2.Connect Volts test leads to both solenoid switch terminals. Battery voltage should be seen at this time
3.Disable the ignition so the vehicle will not start.
4.Turn the key switch to crank the engine while reading the voltage
5.Test Conclusion : Less than 0.5 volt drop indicates good connections. If the voltage drop is higher, measure the voltage across the switches and wires along the circuit to further isolate.
KEY SWITCH
TRANSMISSION
SAFETY
SWITCH
STARTER
BATTERY
CHASSIS | SOLENOID RELAY |
|
Figure 5
Connection For SOLENOID CONTROL SWITCH TEST
6