Stator checking procedure.

(c) Shorted windings in the stator are in-

dicated if all other electrical checks are normal, but

the alternator does not supply rated output. For

alternator specifications refer to table 5-1.

ME 3500-624-34/5-2

Figure 5-2. Checking rotor for grounds, shorts and opens.

(b) To check the rotor for an open field,

connect a test tight or an ohmmeter to each of the

slip rings. as shown in figure .5-2. If the lamp fails to

light or the ohmmeter reading is high (infinite), the

ME 3930-624-34/5-3

winding is open.

(c) Connect a voltmeter and battery in series

Figure 5-3. Checking stator windings.

with the slip rings. If the reading on the ammeter is

above 2.9-2.3 amps. a shorted winding is indicated.

The alternator must be replaced. Refer to figure 5-

(4) Checking the diodes.

(3) Stator checking procedure.

Note. When checking the diode, disconnect the stator.

Note. When checking the statorwindings, remove the

(a) Connect one ohmmeter lead or 12 volt

three stator Iead attaching nuts and separate the stator

test tamp lead to the heat sink frame and the other

assembly from the end frame.

test lead to the diode lead (fig. 5-4). Note meter

(a) Check the stator for grounded windings,

reading or condition of test lamp. Reverse the test

leads and note new meter reading or condition of

Connect the probes of a test tamp or an ohmmeter

from each of the three stator leads in turn to the

test tamp.

(b) A good diode will have a high reading in

stator frame as shown in figure 5-3. If the test tamp

lights or the meter reading is low, the stator is

one direction and a low reading in the other

grounded. The alternator must be replaced if the

direction. If the meter reading or the condition of

the test lamp is similar in both readings, the diode is

ground cannot be located and repaired.

(b) Connect the test tamp or ohmmeter

defective and must be replaced.

(c) Repeat the above outlined procedure for

between the stator leads successively as illustrated

ail six diodes.

in figure .5-3. If the lamp fails to light or the meter

reading is high. the windings are open. If the open

condition in stator cannot be remedied, the

alternator must be replaced.

5-3