DESCRIPTION
Note. Some models are available with Hitachi alternators. See appropriate ALTERNATORS & REGULATORS - HITACHI article.
Mitsubishi alternators are conventional 3-phase, self-rectifying type units containing 6 diodes (3 positive and 3 negative). These diodes are used to rectify current. A case-mounted Integrated Circuit (IC) regulator is used on all models.
BELT TENSION
| Application | (1) Deflection In. (mm) |
|---|---|
| NX | 9/32 (7) |
| Sentra | 5/16 (8) |
| Stanza | 1/4 (6) |
| (1) Deflection is with 22 lbs. (10 kg) pressure applied midway on the longest belt run. | |
| (1) | Deflection is with 22 lbs. (10 kg) pressure applied midway on the longest belt run. |
ALTERNATOR BELT ADJUSTMENT
ON-VEHICLE TESTING
Note. Check alternator wire harness connections and drive belt tension. Ensure battery is fully charged before testing. Wait at least 30 seconds after starting engine before measuring voltage.
Alternator test
- Ensure battery is fully charged before testing. Turn ignition on and check charge indicator light on instrument panel. If light comes on, go to step 3). NOTE: Terminals "B", "E", "L" and "S" are marked on the alternator's rear cover.
- If light is off, disconnect alternator connector and ground wire of terminal "L". If light comes on, replace regulator and alternator. If light remains off, replace indicator bulb and retest.
- Start and run engine at idle. If charge indicator light is dim, flickers or remains on (bright), repair alternator. If light goes off, run engine at 1500 RPM and turn on headlights. If light remains off, go to step 4). If light comes on, replace alternator.
- Run engine at 1500 RPM and measure voltage at terminal "B". If voltage is more than 15.5 volts, replace IC regulator. If voltage is 13-15 volts, alternator and regulator are okay.
Rotor
Connect ohmmeter leads to each of the rotor slip rings. If continuity is present, rotor is okay. If continuity is NOT present, rotor is defective. Connect an ohmmeter lead any slip ring and connect remaining lead to rotor core. If continuity exists, replace rotor assembly.
Note. To test stator or diodes, separate them by unsoldering the connecting wires. Use just enough heat to melt solder. Excess heat will damage diodes.
Stator
Using ohmmeter, check continuity between stator core leads. If continuity is NOT present between leads, replace stator. Connect one ohmmeter lead to stator core. Connect remaining ohmmeter lead, in turn, to each of the stator leads. If continuity is NOT present, stator is good. If continuity exists, stator is grounded and must be replaced.
Diodes
Using an ohmmeter, check continuity of all diodes in both directions. Continuity should exist in only one direction. If continuity exists in both directions, diode is shorted. (Scheme 4) If continuity is NOT present in either direction, diode is open. If any diode is defective, replace entire diode assembly.
Scheme 4
Brushes
Inspect brushes for freedom of movement in holder. Clean brush holder if necessary. Check brushes for cracks and wear. Check brush springs for corrosion or damage. Ensure brushes are not worn beyond minimum length. Refer to ALTERNATOR APPLICATIONS table ALTERNATOR SPECIFICATIONS table.
| Model | Mitsubishi Part No. |
|---|---|
| NX & Sentra (1.6L) | A5T03192 |
| NX & Sentra (2.0L) | A2T13894 |
| Stanza | A2T18792 |
ALTERNATOR APPLICATIONS
| Application | Output Amps @ RPM | (1) Brush Length Inch (mm) |
|---|---|---|
| A5T03192 | 50 @ 2500 | .31 (8) |
| A2T13894 | 65 @ 2500 | .31 (8) |
| A2T18792 | 60 @ 2500 | .31 (8) |
| (1) Minimum brush length. | ||
| (1) | Minimum brush length. |
ALTERNATOR SPECIFICATIONS
CHARGING SYSTEM
| Possible Cause | Action |
|---|---|
| Dead Battery | Check/Replace Battery |
| Bad Cable Connections | Clean/Replace Cables |
| Ignition Switch/Circuit Fault | Check Switch/Circuit |
TROUBLE SHOOTING - NO START CONDITION
| Possible Cause | Action |
|---|---|
| Loose/Worn Alternator Belt | Tighten/Replace Belt |
| Loose Alternator Connections | Check/Repair Connections |
| Warning Light Wiring | Check/Repair Wiring |
| Faulty Stator/Diodes | Test/Repair Alternator |
TROUBLE SHOOTING - CHARGING SYSTEM WARNING LIGHT STAYS ON
| Possible Cause | Action |
|---|---|
| Blown Fuse | Check/Replace Fuse |
| Faulty Alternator | Test Alternator |
| Bad Warning Light Bulb | Test/Replace Bulb |
TROUBLE SHOOTING - WARNING LIGHT OFF WITH IGNITION SWITCH ON
| Possible Cause | Action |
|---|---|
| Alternator Wiring Short | Check/Repair Wiring |
| Faulty Rectifier Bridge | Test/Repair Alternator |
TROUBLE SHOOTING - WARNING LIGHT ON WITH IGNITION SWITCH OFF
| Possible Cause | Action |
|---|---|
| Loose/Worn Alternator Belt | Tighten/Replace Belt |
| Loose Alternator Connections | Check/Repair Connections |
| Faulty Ammeter | Test/Replace Ammeter |
| NOISY Defective Battery | Replace Battery |
| Defective Alternator | Test/Repair Alternator |
| Defective Regulator | Test/Repair Regulator |
TROUBLE SHOOTING - AMMETER INDICATES DISCHARGE
OVERHAUL
Note. A ring is used to lock outer bearing race in alternator's rear cover. It may be necessary to heat bearing housing to remove cover. Use 200 watt soldering iron to heat housing. DO NOT use heat gun, as it may damage diode. (Scheme 5)for exploded view of alternator.
Scheme 5
See also:
• ALTERNATOR APPLICATIONS