Figure 5-1. Alternator, exploded view.

TM 10-3930-621-34

5-4. Testing

a. Use table 5-1 and the referenced figures found on it to test alternator components.

Table 5-1. Alternator Testing

Ref.

Component

fig

Connection

Reading

Result

Rotor

5-2

Ohmmeter from slip ring to shaft.

Very low

Grounded

110 volt test lamp from slip ring to shaft

Lamp lights

Grounded

Ohmmeter across slip rings.

Very high

Open

110 volt test lamp across slip rings.

Lamp fails to light

Open

Battery and ammeter to slip rings, voltmeter

Observe voltmeter and

Compare w/specifications

across slip rings.

ammeter readings.

for shorts

Stator

5-3

Ohmmeter from l ead to frame.

Very low

Grounded

110 .volt test lamp from lead to frame.

Lamp lights

Grounded

Ohmmeter across each pair of leads.

Any reading very high

Open

110 volt test light across each pair of leads.

Fails to light

Open

5-2