Alternators & Regulators - MOTOROLA: Testing

NOTE: Make sure alternator is operating properly before testing voltage regulator. See Motorola Alternators.

With engine off, disconnect output cable from alternator and connect an ammeter (0-60 amperes) in series with output terminal and cable (positive terminal of ammeter connected to output terminal of alternator). Connect a carbon pile load to negative side of ammeter and negative battery terminal. Connect a voltmeter to alternator output terminal and negative battery terminal (positive terminal of voltmeter connected to output terminal of alternator).
Start engine and increase load with carbon pile. Increase engine speed if required, to obtain 10 amperes output current. Operate engine for 15 minutes to stabilize temperature, then check ambient temperature of regulator by placing a thermometer 1" from regulator cover.

Output terminal voltage must be within limits indicated in table at specified ambient temperature. If voltage is not within limits, replace regulator and repeat test. Increase load with carbon pile and engine speed until rated current output is reached. Voltage at output terminal should be at least 13 volts but should not exceed maximum limits indicated in table.

Voltage Specifications

⁽¹⁾Output Voltage

Ambient Temperature

Minimum

Maximum

0°F

14.60

15.40

20°F

14.45

15.25

40°F

14.26

15.08

60°F

14.13

14.92

80°F

13.95

14.75

100°F

13.80

14.60

120F

13.65

14.45

140°F

13.60

14.28

160°F

13.30

14.43

⁽¹⁾	With 10 ampere load.