Generators & Regulators Audi A8 D3

Scheme 1

Scheme 2

DESCRIPTION

Bosch alternators are conventional 3-phase, self-rectifying type alternators. Bosch voltage regulators are transistorized and integral with alternator. Voltage regulators are serviceable.

BELT TENSION

Serpentine belt tension is automatically adjusted by tensioner.

DRIVE BELT ROUTING

Note. Serpentine belt is self-adjusting. For drive belt routing (Scheme 3)

Scheme 3

PRELIMINARY INSPECTION

Verify customer complaint by operating system. Visually inspect for obvious signs of mechanical and electrical damage. Check generator belt tension and condition. Ensure that battery voltage is within specifications. Following manufacturers instructions for load tester, load test battery. See LOAD TEST under ON-VEHICLE TESTING. Inspect for blown fuses and damaged relays. For fuse and/or relay identification, see WIRING DIAGRAMS .

Verify ground connection integrity between engine, body, battery and generator. Check for damaged wiring harnesses and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, check for conditions that might cause an intermittent situation.

LOAD TEST

Note. Manufacturer recommends performing electrolyte specific gravity test, in order to determine battery overall condition. For specific gravity values, see SPECIFIC GRAVITY SPECIFICATIONS table.

Note. On vehicles from 1997-99, it is not necessary to remove battery from vehicle, or disconnect battery terminals. On vehicles from 2000 and on, it is necessary to remove battery for load test.

Connect battery tester cable clamps to battery terminal. Ensure clamps make good contact with battery terminals. Connect battery tester according to tool manufacturer's instructions. Load test battery at approximately one-half cold-cranking amperage rating for 15 seconds while observing battery voltage. If voltage reading is 9.5 volts or more, battery is okay. If voltage reading is less than 9.5 volts, charge battery and retest. If loaded battery voltage is still less than 9.5 volts after charging battery, replace battery.

SPECIFIC GRAVITY SPECIFICATIONS

NO LOAD TEST

Note. If no load voltage is to be measured with battery installed in vehicle, first disconnect ground strap.

Note. Vehicle must not be started or driven with tested battery for at least 2 hours before taking measurements. During this time, DO NOT allow load or additional charge to be applied to battery.

With battery installed, and ignition switched off, check voltage between battery terminals with voltmeter. If no load voltage is 12.5 volts, or higher, battery is okay. If no load voltage is lower than 12.5, recharge battery, and repeat procedure. If battery voltage is still less than 12.5 after charging battery, replace battery.

BRUSHES

Remove generator. See GENERATOR under REMOVAL & INSTALLATION. Remove voltage regulator from back of generator. See VOLTAGE REGULATOR under REMOVAL & INSTALLATION. Brushes are integrated with voltage regulator. Brush wear limit is 0.2" (5 mm).

REMOVAL & INSTALLATION

1997-99

Before disconnecting the battery, please read the following

1. Determine the correct coding for the anti-theft radio
2. Turn ignition OFF.
3. Disconnect battery ground cable.
4. After reconnecting the battery cable, the ECM "Basic Setting" must be re-established using the VAG 1551 scan tool, or equivalent aftermarket scan tool.
5. In the initial learning phase after establishing basic setting, engine idle and driveability may be affected. In this case, let the engine run at idle for a few minutes until the learning process is completed.

2000-03

Before disconnecting the battery, please read the following

1. Determine the correct coding for the anti-theft radio
2. Turn ignition OFF.
3. Disconnect battery ground cable.
4. On vehicles equipped with Audi Telematics by OnStar, switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting vehicle battery. After reconnecting vehicle battery on vehicles equipped with Audi Telematics by OnStar, switch-on the emergency (back-up) battery for the Telematic/Telephone Control Module. The emergency (back-up) battery is mounted behind the Telephone/Telematic Control Module (under rear parcel shelf). (Scheme 4)
5. After reconnecting vehicle battery, re-code and check operation of anti-theft radio.
6. Check operation of clock and power windows.

Scheme 4

1. On vehicles produced from 1997-99, remove noise insulation panel bolts (arrows). (Scheme 5) Remove intake hose from generator.
2. On vehicles produced from 2000 and on, remove noise insulation panel bolts (arrows). (Scheme 6) If panel is obstructed, remove auxiliary heater screws (1). Pull air duct hose off generator.
3. On all vehicles, mark direction of belt. Release tension from belt by pulling belt down by hand (lower arrow), and inserting Drift (3204) (upper arrow). (Scheme 8) Remove belt.
4. Disconnect terminal 30/B+ (1) from generator. (Scheme 7) Disconnect terminal D+ (2).
5. Remove bolts (1). (Scheme 9) Remove bolt (2). Pull generator (4) down, and remove from engine.
6. To install, reverse removal procedure. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/audi/a8/d3-2002-2005/remont/charging-system/#generators-regulators__torque-specifications).

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Removal & Installation (With Freewheel)

1. Remove generator. See «GENERATOR»(/audi/a8/d3-2002-2005/remont/charging-system/#generators-regulators).
2. Using Adapter (3400), counter-hold securing nut. (Scheme 10) Turn generator shaft clockwise to remove.
3. To install, turn generator shaft counterclockwise. Tighten to specification. See «TORQUE SPECIFICATIONS»(/audi/a8/d3-2002-2005/remont/charging-system/#generators-regulators__torque-specifications). Clip protective cap onto freewheel pulley.

Scheme 10

Removal & Installation (Without Freewheel)

1. Using Socket (3310), counter-hold securing nut. (Scheme 11) Turn generator shaft clockwise to remove.
2. To install, turn generator shaft counterclockwise. Tighten to specification. See «TORQUE SPECIFICATIONS»(/audi/a8/d3-2002-2005/remont/charging-system/#generators-regulators__torque-specifications).

Scheme 11

VOLTAGE REGULATOR

Note. Manufacturer does not provide specific procedures for removal and installation of voltage regulator. As an aid in removal and installation (Scheme 12)or (Scheme 13).

Scheme 12

Scheme 13

OVERHAUL

Note. Manufacturer recommends replacing generator as an assembly. Overhaul procedures are not available.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

WIRING DIAGRAMS

Note. See CHARGING SYSTEM in appropriate SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

See also:
• LOAD TEST
• WIRING DIAGRAMS
• SPECIFIC GRAVITY SPECIFICATIONS
• VOLTAGE REGULATOR
• TORQUE SPECIFICATIONS