| Purpose |
To check voltage at coil SW terminal under starting conditions |
| Test connections |
Voltmeter leads to coil SW terminal and earth, and a jumper lead connecting the coil CB terminal to earth, to prevent the engine from starting. |
| Result |
When the starter is turning the engine, and the ignition switched on, the voltmeter reading should not be less than 9 volts. A lower reading indicates a weak battery, defective cables or connections, or a faulty starter motor taking excessive current causing an abnormal volt drop. |
Test 2
| Purpose |
To check voltage at coil SW terminal when the contact breaker points are closed |
| Test connections |
As for test 1. The jumper lead is used to ensure that test is not affected by possible resistance in the contact breaker points or faulty earthing of the fixed contact point.
|
| Result |
Voltmeter reading should not be less than 5.8 volts. Lower readings are caused by defective battery, loose connections, de-fective cables or ballast resistance. |
Note: The difference between the correct figures for tests I and 2 are due to the ballast resistance being in circuit for test 2 which it was not for test I.
Test 3
| Purpose |
To check contact breaker point resistance, lead to distributor moveable point, and earthing of distributor. |
| Test connections |
Voltmeter leads to coil CB terminal and earth (cylinder block), and engine turned to CLOSE THE CONTACT BREAKER POINTS. |
| Result |
Voltmeter readings should not be higher than 0.1 volts. Higher readings are caused by dirty or defective contact breaker points, defective lead from the coil CB terminal to the moveable contact breaker connection, or faulty earthing of the contact mounting plate or distributor body. |
|
Test 4 - (If needed)
| Purpose |
To locate point at which volt drop occurs. |
| Test connections |
The voltmeter is connected to the engine connections cylinder block and to the shown in Fig. 98 In the following order, and each terminal checked for tightness as correct voltmeter readings are not an indication that terminals are tight. |
| Result |
Voltmeter readings should not be higher than 0.1 volts. Higher readings are caused by dirty or defective contact breaker points, defective lead from the coil CB terminal to the moveable contact breaker connection, or faulty earthing of the contact mounting plate or distributor body. |
Results
| Voltmeter Connections |
Correct Voltage
|
| Battery + and —Battery + |
Not less than 12.4. |
| Battery + frame by earth lead connection. |
12.2 with ignition ON and points closed. |
| Live terminal A on starter solenoid and cylinder block. |
12.2 with ignition ON and points closed. |
| Terminal B on regulator and cylinder block. |
11.9 with ignition ON and points closed. |
| Terminal D on resistance and cylinder block. |
11.6 with ignition ON and points closed. |
| SW terminal on coil and cylinder block. |
6.6with ignition ON and points closed. |
| CB terminal on coil and cylinder block. |
0.1 max. with Ignition ON and points closed. |
| P — contact breaker terminal, inside distributor, and cylinder block. |
0.1 max. with Ignition ON and points closed. |
Note: The ballast resistor reduces the battery voltage to about 6.6 when the contact breaker points are closed. If a voltage reading is taken at the call SW terminal with the contact breaker points open, battery voltage will be recorded because of the very small current taken by the voltmeter.
Contact Breaker Points
The breaker point assembly consists of the stationary point bracket assembly, breaker arm and the primary wire terminal.
Breaker points should be inspected, cleaned and ad-justed as necessary. Breaker points can be cleaned with chloroform and a stiff bristle brush. Replace the breaker point assembly if the contacts are badly burned or
|
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