Generator & Regulator BMW Z3 E36

DESCRIPTION

Bosch conventional 3-phase, self-rectifying type generators use 3 exciter diodes connected to stator windings. These diodes turn off generator indicator light and supply power to voltage regulator while engine is running. Bosch voltage regulators are transistorized and integral with generator.

An unloader relay is used on some models. With ignition on and engine off, the relay receives battery voltage (B+) through fuse No. 28 and is grounded through terminal D+ of the generator. The relay energizes and switches ground to some accessories. When the engine is running and the generator begins to charge, battery positive voltage is also applied to terminal D+ to switch off the relay.

TROUBLE SHOOTING

Note. See TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.

BATTERY DISCONNECT PROCEDURE

Note. If ignition is not turned off when battery is disconnected, fault memories may be set in some control units.

Disconnecting Battery

1. Turn ignition off. DO NOT disconnect battery leads and leads from alternator and starter motor while engine is running.
2. There is a danger of mixing up battery leads. If battery positive and negative leads are the same color, follow the polarity to the battery. Then mark and cover leads.
3. On vehicles with radio code, radio code must be re-entered after connecting battery. Obtain radio code card from customer. Make a note of stored stations. Stored setting of on-board computer and clock will be lost.
4. Detach terminal of battery negative lead from car battery and secondary battery, if fitted. DO NOT pull lever off pole shoes by force. DO NOT remove socket-head cap screw of IBS. Cover battery negative terminals and secure.

Connecting Battery

1. When connecting battery, ignition must be off. No one must be in the car when battery is connected. AIRBAG module may activate when power is connected.
2. All available central keys must be coded for cars with first generation infrared transmitter locking systems.
3. If equipped, use radio code to enable radio. Reset radio station presets.
4. To set clock, time must be showing in instrument cluster display. Turn ignition on. To set ahead, turn button on right of tachometer to right. To set back, turn button to left. Adjustment speed will increase the longer the button is held. Pressing button will alternate setting from 12 hour to 24 hour mode.
5. On board computer settings will begin from zero.
6. Driveability problems may exist until computer systems have completed a relearn cycle. Vehicle may have to be driven for a few minutes before engine runs normally.
7. On vehicles equipped with sun roof, recalibration of sun roof may be necessary. There is no anti-trapping protection during recalibration. Perform the following procedure: Press and hold sun roof switch in lift direction. In case of delayed starting or sudden stopping of sun roof, continue pressing switch in lift direction until roof reaches lift position. After reaching full lift position, hold switch in position for at least 20 seconds more. Calibration is completed when sun roof in lift position bounces slightly in lift direction. Release switch for no more than 5 seconds. Hold down switch in raising position direction until sun roof has returned to closed position after a complete opening movement. Release switch. Carry out function check (one-touch function, anti-trapping protection and, if necessary, comfort function).

Except 3-Series

1. Check charging system fuse No. 28. Replace fuse if necessary. Remove unloader relay. Turn ignition on. On 5-series, check for battery voltage at relay socket terminals No. 5 and 8 (Green/White wires). On 7-series, check for battery voltage at relay socket terminals No. 4 and 5 (Green/White wires). On all models, if battery voltage is present, go to next step. If battery voltage is not present, repair circuits.
2. Ensure relay socket terminal No. 2 (Brown/Black wire) is grounded. If socket terminal is grounded, go to next step. If socket terminal is not grounded, repair ground circuit.
3. Start engine and ensure charge indicator light goes out. If charge indicator light remains on, check charging system. If charge indicator light goes out, go to next step.
4. With engine running, ensure a minimum of 12 volts exists at relay socket terminal No. 4 (5-series) or terminal No. 8 (7-series). If voltage is as specified, go to next step to check voltage to accessories. If voltage is not as specified, repair wire to generator.
5. Turn ignition switch off. Connect a fused jumper wire between relay socket terminals No. 5 (Green/White wire) and No. 6 (Red wire). Turn ignition on. Ensure battery voltage is supplied to relay operated systems (i.e., rear defogger relay, heated seats, automatic A/C, etc.). If voltage is not present to these systems, repair circuits. If voltage is present to these systems, go to next step.
6. Install unloader relay. Start engine and ensure battery voltage is present at relay operated systems. If relay does not work, replace unloader relay.

WIRING CONTINUITY TEST

1. Connect voltmeter between generator B+ terminal and ground. Voltmeter should indicate battery voltage. If battery voltage is not indicated, check wiring between generator and battery.
2. Turn ignition on and ensure generator indicator light comes on. If light does not come on, check indicator light bulb and wiring between generator and warning light.

OUTPUT TEST

1. Ensure connections at battery, generator, and starter are clean and tight. Ensure generator, engine and body are properly grounded.
2. Ensure generator drive belt is tight and in good condition. Connect charging system tester according to manufacturer's instructions. Connect voltmeter leads to battery terminals.
3. Start and operate engine at 3000 RPM. Adjust carbon pile on tester to obtain maximum generator output. DO NOT allow voltage to drop to less than 12.6 volts.
4. Generator output should equal generator rated output. If reading is 16-20 amps less than generator rating, replace regulator and retest. If output is still low, repair or replace generator.

REGULATOR CONTROL VOLTAGE TEST

1. Connect charging system tester according to manufacturer's instructions. Connect voltmeter leads to battery terminals. Start and operate engine at 3000 RPM.
2. Operate engine until voltage stops rising. Voltage should be 13.5-14.2 volts. If reading is incorrect, remove regulator and ensure brushes are longer than 0.198" (5.0 mm). Replace if necessary.
3. If brushes are okay and regulator fails to keep voltage within specified limits, replace regulator and retest. If voltage is still incorrect, repair or replace generator.

DIODE ASSEMBLY

1. Place ohmmeter on X100 scale. Connect ohmmeter leads, in turn, between B+ terminal and each of the 3 stator terminals. (Scheme 1) Reverse leads. Ohmmeter should indicate continuity in one direc tion only.
2. Connect ohmmeter leads, in turn, between negative plate and each of the 3 stator terminals. Reverse leads. Ohmmeter should indicate continuity in one direction only.
3. Connect ohmmeter leads, in turn, between D+ terminal and each of the 3 stator terminals. Reverse leads. Ohmmeter should indicate continuity in one direction only. Replace diode assembly if continuity is not as specified.

Scheme 1

STATOR

1. Place ohmmeter on lowest scale. Measure resistance between 2 of the 3 sets of wires. Move one ohmmeter lead to the other set of wires. Check resistance between the remaining set of wires. Resistance values must be identical. If resistance is incorrect, stator has open or shorted windings and must be replaced.
2. Place ohmmeter on X1000 scale. Connect ohmmeter between stator core and each stator lead. Continuity should not exist. If continuity exists, stator is grounded and must be replaced.

ROTOR

1. Place ohmmeter on lowest scale. Connect ohmmeter across slip rings. Ensure resistance is within specification. See ROTOR RESISTANCE table.
2. If resistance is too low, rotor has short circuit and must be replaced. If resistance is infinite (no continuity), rotor has open circuit and must be replaced.
3. Place ohmmeter on X1000 scale. Connect ohmmeter between rotor core and either slip ring. Continuity should not exist. If continuity exists, rotor is grounded and must be replaced.

ROTOR RESISTANCE

Removal

1. Disconnect battery. Remove air filter housing. Using Pulley Holder (11-5-030) and 32-mm Wrench (11-5-040), turn cooling fan nut clockwise (left-hand thread) to remove cooling fan.
2. Note serpentine belt routing. Insert socket into drive belt tensioner bolt. Compress tensioner slowly and remove belt.
3. Remove mounting bolts and cooling duct (if equipped). Remove wiring and generator.

Installation

To install, reverse removal procedure. Ensure serpentine belt is correctly routed and seated in grooves. Use Pulley Holder (11-5-030) to hold water pump pulley, and turn 32-mm Wrench (11-5-040) counterclockwise (left-hand thread) to tighten cooling fan nut to 22 ft. lbs. (30 N.m).

Note. Tighten cooling fan nut to 29 ft. lbs. (40 N.m) if a conventional 32-mm open end wrench is used.

OVERHAUL

For overhaul procedures, see appropriate illustration for exploded view of generator. (Scheme 2)or (Scheme 3).

Scheme 2

Scheme 3

GENERAL SPECIFICATIONS

ALTERNATOR WITH DRIVE AND MOUNTING PARTS E39

TORQUE SPECIFICATIONS

ALTERNATOR WITH DRIVE AND MOUNTING PARTS

WIRING DIAGRAMS

Note. Wiring diagrams for BMW 5 and 7-series vehicles are not available at time of publication.

Charging System Wiring Diagram (1997 318i, 318is, 328i, 328is & M3; 1998 318i, 323i Convertible, 323is, 328i, 328i Convertible, 328is & M3). Scheme 4

Charging System Wiring Diagram (1997-98 318ti). Scheme 5

Charging System Wiring Diagram (1997-98 Z3). Scheme 6