Models with hitachi alternators:
- Datsun 510
- Datsun 521 Pickup
- Datsun 520 Pickup
- Datsun 240Z Sports
- Subaru 1100
- Subaru 1300
CHANGES, CAUTIONS & CORRECTIONS
BATTERY INSTALLATION, BATTERY CHARGING, OR USING A BOOSTER BATTERY TO START ENGINE CAUTION - Reversed polarity or excessive voltage will result in extensive damage to alternator system. NOTE - the following to prevent damage.
Battery Installation - Negative battery terminal must be connected to ground. Positive terminal must be disconnected from battery. Do not use "Fast Charger" to provide starting voltage.
Booster Battery (Used To Start Engine) - Booster battery must be connected with negative lead to negative terminal of battery and positive lead to positive terminal of battery. Do not reverse battery leads.
DESCRIPTION
Hitachi alternators are conventional thee-phase, self-rectifying type alternators. Six diodes (three positive and three negative) are used to rectify current.
Application Hitachi Part No.
Datsun
520 (1966-67)...........................................LT119-07
510 (1968-71)...........................................LT130-41
521 (1969-71)...........................................LT130-41
240Z (1970-71).........................................LT145-35
Subaru
1100 (1971)..............................................LT170-75
1300 (1971)..............................................LT130-59
SPECIFICATIONS
At 2500 Alternator RPM
Alternator Amps Volts
LT119-07.........................19.5.........................14
LT130-41...........................22..........................14
LT135-05...........................33..........................14
LT145-35...........................34..........................14
LT170-75 & 130-59............27..........................14
Nominal Output
Alternator Volt Amps
LT119-07..........................12..........................25
LT130-41..........................12..........................30
LT133-05..........................12..........................33
LT145-35..........................12..........................45
LT170-75 & 130-59...........12..........................30
Rotation - Clockwise at drive end.
Field Coil Resistance - 4.47 Ohms measured at slip rings at normal ambient temperature.
Alternator Min. Brush Length
LT130-41.......................................... .256" (6.5 mm)
LT133-05.......................................... .275" (7.0 mm)
LT145-35.......................................... .295" (7.5 mm)
LT170-75 & 130 -59........................... .470" (12 mm)
Brush Spring Tension - Nominal........ .77 lb (.35 kg.)
Minimum.......... .44 lb (.2 kg)
TESTING
ON CAR TEST
Whenever battery is discharged and charging rate is low, following test should be performed to determine
whether fault lies in alternator or regulator. First, place ammeter between "A" terminal of regulator and battery. Disconnect wire at "F" terminal of regulator and touch lead to "A" terminal of regulator. If charging current remains constant, alternator is defective. But if current increases greatly, then regulator is faulty.
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| CIRCUIT FOR ALTERNATOR OUTPUT TEST |
ALTERNATOR OUTPUT
NOTE - Battery used for this test should be fully harged.
For output test, remove alternator from vehicle and connect wiring as shown in illustration. Drive alternator with a motor. Run alternator up to a speed where there is no reverse current flow to field coil. At this point alternator speed should be approximately 1000 RPM. Next, increase alternator RPM while at the same time, increasing load resistance to prevent voltage output from becoming too high. If alternator is functioning correctly, output current should be close to specified value at specified RPM and voltage, see specifications.
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| CHECKING DIODES |
Drive End Bearing - Remove bearing retainer by unscrewing screws and press out bearing using a suitable press.
Rear Bearing - Remove rear bearing from housing using a suitable press or bearing puller.
REASSEMBLY
Reassemble alternator by reversing disassembly procedure. During assembly, always make sure polarity of diodes is correct.
OVERHAUL
DISASSEMBLY
1) Unscrew and remove through bolts. Separate diode end housing from drive end housing assembly by hitting front bracket lightly with a soft mallet.
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| INSTALLING DIODES |
2) Place rear shaft carefully into vice so as not to damage rear shaft. Remove pulley nut, pulley fan and spacer. Now, remove rotor from drive end housing assembly by lightly hitting drive end housing with a soft mallet.
3) To separate stator from diode end housing assembly, melt solder from three negatie diode leads and from each wire between diodes and disconnect leads. CAUTION - If internal temperature of a diode rises over 300 degrees Fahrenheit (150 degrees Celcius), diode will be destroyed. Therefore, use a electric solder iron of 100-200 watt capacity for approximately two seconds to safely unsolder connections. Remove brush cover by unscrewing setscrews. Unsolder "N" terminal (yellow color) lead wire, then separate diode end housing and stator.
4) Remove heat sink and brush holder from rear cover by removing setscrews. Disassemble brush holder. Unsolder lead wire "F" (black/white), lead wire "E" (black color) and brush holder wires (negative and positive).
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| HITACHI ALTERNATOR ASSEMBLY |
TESTING
Rotor - To test for open circuit, connect an ohmmeter between rotor slip rings. If ohmmeter reading is high, windings are open. A good rotor should have a resistance of approximately 4.46 ohms at normal ambient temperature. To test for grounded coils, connect an ohmmeter between either slip ring and rotor core or shaft. If ohmmeter reading is low, field windings are grounded. Check eccentricity of rotor, using a dial indicator. If eccentricity of rotor exceeds .0039 in. (.10 mm). it must be either repaired or replaced.
Stator - To test for open circuit, connect an ohmmeter successively between neutral lead wire (yellow color) and three stator leads. If ohmmeter reading is high, stator windings are open. To test for grounded coil, connect an ohmmeter from any stator lead to stator frame. If ohmmeter reading is low, windings are grounded. Repair or replace stator as necessry.
Diodes - With diodes disconnected from stator leads, check each diode with ohmmeter as follows.
Connect one ohmmeter lead to diode lead and connect other ohmmeter lead to heat sink and note reading. Reverse ohmmeter leads, and note reading. If both readings are very low or very high, diode is defective and must be replaced. A good will give you one low and and one high reading.
Connect one ohmmeter lead to diode lead and connect other ohmmeter lead to heat sink and note reading. Reverse ohmmeter leads, and note reading. If both readings are very low or very high, diode is defective and must be replaced. A good will give you one low and and one high reading.
