N3 Series Brushless Alternators Caterpillar

Stator Winding Continuity Test

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Illustration 1	g00868876
(1) Stator (A) Stator lead (B) Stator lead (C) Stator lead

1. Remove the stator (1) from the frame assembly.

2. Unsolder all the stator leads from the rectifier: (A), (B) and (C)

3. Connect the multimeter leads across a pair of stator leads: (AB), (AC) and (BC) .

4. Measure the resistance between the stator leads.

   Expected Results:

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   Table 1

   Alternator	Resistance
   7N-9728	.25 ± .05 ohms
   9G-9538	.20 ± .05 ohms
   100-5046	.20 ± .05 ohms

   Results:

   OK - The resistance is within tolerance. Repeat steps 1 through 4 for all other possible pairs of stator leads: (AB), (AC) and (BC). If all of the results are OK, the stator is normal. STOP.

   NOT OK - The resistance is above tolerance. The stator (1) has an open circuit. Replace the stator. STOP.

   NOT OK - The resistance is below tolerance. Stator (1) has a short circuit. Replace the stator. STOP.

Stator Winding Ground Test

Illustration 2	g00868878
(1) Stator assembly (2) Test lead to frame (A) Stator lead (B) Stator lead (C) Stator lead

1. The stator assembly remains removed from the alternator.

2. Connect the multimeter leads acrossthe frame (2) and one of the stator leads (A), (B), or (C) .

3. Measure the resistance.

   Expected Result: The resistance is greater than 100000 ohms.

   Results:

   OK - The resistance is greater than 100000 ohms. Repeat steps 1 to 3 for the other stator leads (A), (B), or (C). If all of the results are OK, the stator is normal. STOP.

   NOT OK - The resistance is NOT greater than 100000 ohms. Stator (1) is shorted to the frame. Replace the stator. STOP.