Testing And AdjustingTesting And Adjusting

Testing And Adjusting

Troubleshooting Troubleshooting T

Troubleshooting can be difficult. Following roubleshooting can be difficult. Following is a list is a list of possible problems. Tof possible problems. To make a o make a repair to a problem, make reference torepair to a problem, make reference to the probable cause.

the probable cause.

This list of problems and probable causes will only give an i

This list of problems and probable causes will only give an i ndication of where a possible problem can be and what repairsndication of where a possible problem can be and what repairs are needed. Sometimes more or other repair work

are needed. Sometimes more or other repair work is needed beyond the recommendations in the is needed beyond the recommendations in the list. Remember that alist. Remember that a problem is not normally caused by one part, but by t

problem is not normally caused by one part, but by t he relation of one part with other parts. This lihe relation of one part with other parts. This li st cannot give allst cannot give all possible problems and probable causes. The serviceman must find t

possible problems and probable causes. The serviceman must find t he problem and its source, he problem and its source, then make the necessarythen make the necessary repairs.

repairs.

Troubleshooting Problem roubleshooting Problem ListList 1. Alternator Does Not Charge.

1. Alternator Does Not Charge.

2. Alternator Charge

2. Alternator Charge Rate Is Low Rate Is Low Or Not RegularOr Not Regular..

3. Alternator Charges

3. Alternator Charges TToo Much.oo Much.

4. Alternator Is

4. Alternator Is NoisyNoisy..

Troubleshooting roubleshooting ProblemsProblems

Problem 1: Alternator Does Not Charge.

Probable Cause:

1. Loose Drive Belt For Alternator:

Adjust the alternator drive belt.

2. Loose Alternator Drive Pulley:

Check the key groove in the pulley for wear

Check the key groove in the pulley for wear. If the groove is worn, install a . If the groove is worn, install a new pulleynew pulley. Tighten the pulley nut to . Tighten the pulley nut to thethe correct torque. See Specifications.

correct torque. See Specifications.

3. Charging Or Ground Return Circuit Or Battery

3. Charging Or Ground Return Circuit Or Battery Connections Are Defective:Connections Are Defective:

Inspect all cables and connections.

Inspect all cables and connections. Clean and tighten all Clean and tighten all connections. Replace defective parts.connections. Replace defective parts.

4. Rotor Field Winding Or Regulator Is Defective:

Install a new roto

Install a new roto r or regulator assemblyr or regulator assembly..

Problem 2: Alternator Charge Rate Is Low Or Not Regular.

Probable Cause:

1. Loose Drive Belt For Alternator:

Adjust the alternator drive belt.

2. Loose Alternator Drive Pulley:

Check the key groove in the pulley for wear

correct torque. See Specifications.

3. Charging Or Ground Return Circuit Or Battery

3. Charging Or Ground Return Circuit Or Battery Connections Defective:Connections Defective:

Inspect all cables and connections.

Inspect all cables and connections. Clean and tighten all Clean and tighten all connections. Replace defective parts.connections. Replace defective parts.

4. Regulator Is Defective:

Install a

Install a new regulator assembly.new regulator assembly.

5. Rectifier Is Defective:

Install a new rectifier.

6. Brushes Are Worn Or Dirty:

Install new brushes.

Problem 3: Alternator Charges Too Much.

Probable Cause:

1. Alternator Or Regulator Has Loo

1. Alternator Or Regulator Has Loo se Connections:se Connections:

Tighten all connections to

Tighten all connections to the alternator or regulatorthe alternator or regulator..

2. Regulator Is Defective:

Install a

Install a new regulator assembly.new regulator assembly.

Problem 4: Alternator

Problem 4: Alternator Is Noisy.Is Noisy.

Probable Cause:

1. Drive Belt

1. Drive Belt For Alternator Is Worn Or Defective:For Alternator Is Worn Or Defective:

Install a new drive

Install a new drive belt for the belt for the alternatoralternator..

2. Loose Alternator Drive Pulley:

Check the key groove in the pulley for wear

correct torque. See Specifications.

3. Drive Belt And Drive Pulley For Alternator Are Not In Alignment:

Make an adjustment to put the drive belt and drive pulley in correct alignment.

4. Alternator Bearings Are

4. Alternator Bearings Are Worn:Worn:

Install new

Install new bearings in the bearings in the alternatoralternator..

Alternator Output Test

1. Put the multimeter positive (+) lead on

1. Put the multimeter positive (+) lead on the B+ terminal of the alternatorthe B+ terminal of the alternator. Put the negative (-) . Put the negative (-) lead on the negative (-)lead on the negative (-) terminal or frame of

terminal or frame of the alternatorthe alternator. Put the . Put the clamp-on ammeter around the positive output clamp-on ammeter around the positive output wire of the wire of the alternatoralternator..

2. Turn off all electrical accessories. With the fuel off, crank the engine for 30 seconds. Wait two minutes to let the starting 2. Turn off all electrical accessories. With the fuel off, crank the engine for 30 seconds. Wait two minutes to let the starting motor cool. If the system appears to operate at the specifications, crank the engine again fo

motor cool. If the system appears to operate at the specifications, crank the engine again fo r 30 seconds.r 30 seconds.

NOTE: Cranking the engine for 30 seconds partially discharges the batteries in order to do a charging test. If batteries are NOTE: Cranking the engine for 30 seconds partially discharges the batteries in order to do a charging test. If batteries are already low in charge, skip

already low in charge, skip this step. Jump-start engine or this step. Jump-start engine or charge batteries as required.charge batteries as required.

3. Start the engine and run at

3. Start the engine and run at full throttle.full throttle.

NOTE: Full throttle approximates the required drive pulley s

NOTE: Full throttle approximates the required drive pulley s peed of 5000 rpm.peed of 5000 rpm.

4. Immediately check output

4. Immediately check output current. When operating correctlycurrent. When operating correctly, this initial , this initial charging current is equal to charging current is equal to or greater than theor greater than the full output current shown below:

full output current shown below:

8C5535 ... 29A

5. The alternator output should stabilize within output should stabilize within approximately 10 minutes at approximately 10 minutes at full throttle (possibly lofull throttle (possibly lo ngernger, depending upon, depending upon battery size, condition and al

battery size, condition and al ternator rating). When operating correctlyternator rating). When operating correctly, the alternator , the alternator output voltage is:output voltage is:

12V System ... 14.0 ± 0.5V 12V System ... 14.0 ± 0.5V 24V System ... 27.5 ± 1.0V 24V System ... 27.5 ± 1.0V If the alternator

If the alternator is NOT performing within specifications, see the is NOT performing within specifications, see the Fault Condition and Possible Causes chart.Fault Condition and Possible Causes chart.

6. The charging current during this period should taper off to less than approximately 10

6. The charging current during this period should taper off to less than approximately 10 amps, depending again uponamps, depending again upon battery and alternator capacities. If

battery and alternator capacities. If the charging current does NOT decrease as specified, see the Fault Conditions the charging current does NOT decrease as specified, see the Fault Conditions andand Possible Causes chart.

7. The K1/N1 alternators are self-excited at high speeds. For this reason, alternators are self-excited at high speeds. For this reason, they are turned on they are turned on by the battery, through theby the battery, through the ignition or key start switch, to start

ignition or key start switch, to start the charging process at low speed. They are turned on any time the ignition othe charging process at low speed. They are turned on any time the ignition o r keyr key start switch is either i

start switch is either i n the ON or n the ON or STASTART position. The charging circuit RT position. The charging circuit shown above is for shown above is for the 7T2876 the 7T2876 AlternatorAlternator. If t. If therehere

is low or no alternator output, c

is low or no alternator output, c heck the circuit between the key start switch and the alternator for an open. heck the circuit between the key start switch and the alternator for an open. Also checkAlso check the resistor and diode (if equipped). The resistance of the resistors should be as follows:

the resistor and diode (if equipped). The resistance of the resistors should be as follows:

7T1183 (7T2876 Alternator) ... 22 ± 4 ohms 7T1183 (7T2876 Alternator) ... 22 ± 4 ohms 6T7864 (9W3043 Alternators) ... 39 ± 2 ohms 6T7864 (9W3043 Alternators) ... 39 ± 2 ohms 8. On lift trucks, check t

8. On lift trucks, check t he alternator light to make sure its working properlyhe alternator light to make sure its working properly. Also, if a machine is . Also, if a machine is jump started becausejump started because the battery is too low, the alternator may not

the battery is too low, the alternator may not have any output. This is because the battery may be too have any output. This is because the battery may be too low to send currentlow to send current to the alternator

to the alternator. The alternator needs current . The alternator needs current to start the charging process.to start the charging process.

Regulator Test Regulator Test

If the alternator does not have the correct output, t

If the alternator does not have the correct output, t he field can be grounded on the 8C5535 and 2Y4212 he field can be grounded on the 8C5535 and 2Y4212 alternators. Thisalternators. This can be done on the machine to determine if t

can be done on the machine to determine if t he regulator is bad. Do the procedure that follows:he regulator is bad. Do the procedure that follows:

NOTE: The 7T2876, 9W3043, 2Y8310,

NOTE: The 7T2876, 9W3043, 2Y8310, 3E7295 and 9X0341 alternators do not 3E7295 and 9X0341 alternators do not have an external DF terminal. Therefore,have an external DF terminal. Therefore, the field on

the field on these alternators cannot be tthese alternators cannot be t urned on externally.urned on externally.

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Alternator Alternator

(1) Jumper wire. (2) D+ terminal. (3) DF

(1) Jumper wire. (2) D+ terminal. (3) DF terminal.terminal.

1. Repeat Steps 1-3 of Machine Tes

1. Repeat Steps 1-3 of Machine Test. Ground the field by connecting jumper wire (1) from Dt. Ground the field by connecting jumper wire (1) from D + terminal (2) to DF terminal+ terminal (2) to DF terminal (3) as shown. This calls for full alternator output.

(3) as shown. This calls for full alternator output.

2. If output is

2. If output is now within 10 amps of rated output, the regulator is bad and now within 10 amps of rated output, the regulator is bad and must be replaced.must be replaced.

3. If output is

3. If output is not within 10 amps of not within 10 amps of rated output, the alternator must be disassembled for component testing. Seerated output, the alternator must be disassembled for component testing. See Alternator Component

Alternator Component TTests.ests.

Bench Test Bench Test

Put the alternator on an alternator test

Put the alternator on an alternator test bench. The maximum current output and regulated voltage should be the same asbench. The maximum current output and regulated voltage should be the same as shown in the machine test.

shown in the machine test.

Alternator Component Tests Alternator Component Tests

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Regulator Test Regulator Test Ver imagen Ver imagen

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Test Circuit For Regulator Test (K1 Shown) Test Circuit For Regulator Test (K1 Shown)

This test can be performed to determine an alternator or regulator malfunction. This test does not

This test can be performed to determine an alternator or regulator malfunction. This test does not cover all of the failurecover all of the failure possibilities, but verifies a few

possibilities, but verifies a few common problems. See the Tescommon problems. See the Test Equipment Chart for t Equipment Chart for the equipment needed for this the equipment needed for this test.test.

Alternator output voltage is regulated by controlling field coil current. The regulator senses output voltage. If t

Alternator output voltage is regulated by controlling field coil current. The regulator senses output voltage. If t he voltagehe voltage is low, the regulator allows field current flow and the voltage builds. When output voltage exceeds the upper limit, field is low, the regulator allows field current flow and the voltage builds. When output voltage exceeds the upper limit, field current is turned off. The output voltage of a properly functioning alternator and regulator is:

current is turned off. The output voltage of a properly functioning alternator and regulator is:

12V System ... 14.0 ± 0.5V 12V System ... 14.0 ± 0.5V 24V System ... 27.5 ± 1.0V 24V System ... 27.5 ± 1.0V

The voltage should not vary more than approximately 0.3V during this process. This test measures voltage when the The voltage should not vary more than approximately 0.3V during this process. This test measures voltage when the regulator turns field current on and off and determines if there is an

regulator turns field current on and off and determines if there is an open or short in the diode trio (exciter diodes), fieldopen or short in the diode trio (exciter diodes), field coil or regulator.

coil or regulator.

1. Connect variable power source (VPS) positive (+) lead to the alternator B+ and D+ terminals as shown. Connect VPS 1. Connect variable power source (VPS) positive (+) lead to the alternator B+ and D+ terminals as shown. Connect VPS negative (-) lead to the alternator B- t

negative (-) lead to the alternator B- t erminal or frame ground.erminal or frame ground.

2. Adjust the voltage of the

2. Adjust the voltage of the VPS until ammeter (A) first indicates current drawVPS until ammeter (A) first indicates current draw. Measure voltage (V) and write this. Measure voltage (V) and write this measurement down as turn-on voltage. When

measurement down as turn-on voltage. When correctly operating, the turn-on voltage is:correctly operating, the turn-on voltage is:

12V System ... 14.0 ± 0.5V 12V System ... 14.0 ± 0.5V 24V System ... 27.5 ± 1.0V 24V System ... 27.5 ± 1.0V

3. Ammeter (A) reads field current. When correctly operating, the field current is:. See Specifications for the K1, 24V 3. Ammeter (A) reads field current. When correctly operating, the field current is:. See Specifications for the K1, 24V alternators.

alternators.

3E7295, 9X0341 Alternators ... 5.1 to 5.7A at 14.0V 3E7295, 9X0341 Alternators ... 5.1 to 5.7A at 14.0V 8C5535, 7T2876 Alternators ... 3.8 to 4.1A at 14.0V 8C5535, 7T2876 Alternators ... 3.8 to 4.1A at 14.0V 9W3043 Alternators ... 2.8 to 3.1A at 27.5V

9W3043 Alternators ... 2.8 to 3.1A at 27.5V 2Y4212 Alternators ... 1.3 to 1.5A at 27.5V 2Y4212 Alternators ... 1.3 to 1.5A at 27.5V 2Y8310 Alternators ... .8 to .9A at 27.5V 2Y8310 Alternators ... .8 to .9A at 27.5V

NOTE: Divide the voltage that first indicates field current by rotor field winding resistance as shown in specifications. This NOTE: Divide the voltage that first indicates field current by rotor field winding resistance as shown in specifications. This will give the correct field current that should be seen on ammeter (A).

will give the correct field current that should be seen on ammeter (A).

4. If ammeter (A) indication is zero amps, the rectifier or fi

4. If ammeter (A) indication is zero amps, the rectifier or fi eld coil or regulator are open. If ammeter (A) indication is tooeld coil or regulator are open. If ammeter (A) indication is too high (see Step 2), the field coil may

high (see Step 2), the field coil may be shorted. The regulator is also bad if the turn-on be shorted. The regulator is also bad if the turn-on voltage is not:voltage is not:

12V System ... 14.0 ± 0.5V 12V System ... 14.0 ± 0.5V 24V System ... 27.5 ± 1.0V 24V System ... 27.5 ± 1.0V

5. If the measurements in Steps 3 and 4

5. If the measurements in Steps 3 and 4 are correct, go to Step 6. If they are correct, go to Step 6. If they are not correct, the alternator and/or regulatorare not correct, the alternator and/or regulator are bad.

are bad.

6. Adjust VPS to the turn-on voltage as

6. Adjust VPS to the turn-on voltage as measured in Step 2. Slowly increase the voltage until ammeter (A) indicates zeromeasured in Step 2. Slowly increase the voltage until ammeter (A) indicates zero amps. Write this voltage down as turn-off voltage.

amps. Write this voltage down as turn-off voltage.

7. The difference between the

7. The difference between the turn-off and turn-on turn-off and turn-on voltages must be no movoltages must be no mo re than 0.3Vre than 0.3V. A larger value . A larger value indicates aindicates a regulator malfunction. Also, ammeter (A) should drop sharply to zero amps. If not, the regulator is

regulator malfunction. Also, ammeter (A) should drop sharply to zero amps. If not, the regulator is faultyfaulty..

8. If the alternator and regulator meet all t

8. If the alternator and regulator meet all t est requirements and there is still a problem, do the additional componentest requirements and there is still a problem, do the additional component tests that follow.

(1) Capacitor mounting screw. (2) Capacitor lead.

1. Disconnect capacitor lead (2) from its t

1. Disconnect capacitor lead (2) from its t erminal on the back of the alternatorerminal on the back of the alternator. Remove the plastic housing from lead (2). Remove the plastic housing from lead (2)

that surrounds the clip.

2. Touch lead (2) to the

2. Touch lead (2) to the capacitor mounting screw (1). This capacitor mounting screw (1). This discharges the capacitordischarges the capacitor..

NOTE: Each time this test is done, the capacitor must be discharged.

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Capacitor Test Capacitor Test

(1) Capacitor mounting screw. (2) Capacitor lead.

3. Put the multimeter on the

3. Put the multimeter on the 20M resistance (Ohms) scale. Connect one multimeter lead to capacitor lead (2). Touch the20M resistance (Ohms) scale. Connect one multimeter lead to capacitor lead (2). Touch the other lead to capacitor mounting screw (1).

other lead to capacitor mounting screw (1).

4. There should be a very low resistance for a short

4. There should be a very low resistance for a short period of time. Then resistance should stabilize above 100 000 ohmsperiod of time. Then resistance should stabilize above 100 000 ohms (meter reading 0.10 or greater).

(meter reading 0.10 or greater).

5. If t

5. If the reading is not he reading is not correct, replace the capacitorcorrect, replace the capacitor..

Rotor Field Winding Tests Rotor Field Winding Tests Rotor Field Winding

Rotor Field Winding Continuity TestContinuity Test Ver imagen

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Rotor Field Winding

Rotor Field Winding Continuity TestContinuity Test (3) Rotor. (4) Slip ring.

(3) Rotor. (4) Slip ring.

1. Put the multimeter on the

1. Put the multimeter on the 200 ohm resistance (Ohms) scale. T200 ohm resistance (Ohms) scale. Touch the meter leads to each slip ring (4) oouch the meter leads to each slip ring (4) o n rotor (3) asn rotor (3) as shown.

shown.

2. The resistance values should be as follows. See specifications for the K1,

2. The resistance values should be as follows. See specifications for the K1, 24 V alternators.24 V alternators.

3E7295, 9X0341 Alternators ... 2.47 to 2.75 ohms 3E7295, 9X0341 Alternators ... 2.47 to 2.75 ohms 8C5535, 7T2876 Alternators ... 3.4 to 3.7 ohms 8C5535, 7T2876 Alternators ... 3.4 to 3.7 ohms 9W3043 Alternators ... 9.0 to 9.9 ohms

9W3043 Alternators ... 9.0 to 9.9 ohms

2Y4212 Alternators ... 18 to 22 ohms 2Y4212 Alternators ... 18 to 22 ohms 2Y8310 Alternators ... 14.4 to 17.6 ohms 2Y8310 Alternators ... 14.4 to 17.6 ohms 3. If the resistance is not

3. If the resistance is not correct, the rotor is open or shorted and must be replaced.correct, the rotor is open or shorted and must be replaced.

Rotor Field Winding Ground Test Rotor Field Winding Ground Test Ver imagen

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Rotor Field Winding Ground Test Rotor Field Winding Ground Test (3) Rotor. (4) Sip ring.

(3) Rotor. (4) Sip ring.

1. Put the multimeter on the

1. Put the multimeter on the 20M resistance (Ohms) scale. T20M resistance (Ohms) scale. Touch the meter leads between each slip ring (4) and the rotorouch the meter leads between each slip ring (4) and the rotor shaft.

shaft.

2. Both readings should be 100 000

In document Motor 3054#2 (Page 46-71)