Generators & Regulators Land Rover Discovery L318

DESCRIPTION & OPERATION

Generator is a 3-phase, field-sensed unit. An electronic voltage regulator controls output voltage by high frequency switching of rotor field circuit. Generator system uses a charge indicator warning light located in instrument panel. When ignition switch is turned to ON position battery voltage is supplied to charge indicator warning light, which illuminates as a bulb check. When generator supplied voltage to charge indicator warning light exceeds battery voltage, charge light ground is cancelled and it will go out. If generator supplied voltage becomes less than battery voltage, charge indicator warning light ground is restored, illuminating bulb to let driver know a malfunction has occurred in charging system.

DRIVE BELT TENSION

A serpentine drive belt is used to drive all accessaries. Accessory drive belt tension is controlled by a belt tensioner. Check accessory drive belt for signs of splits, fraying, oil contamination and wear. Replace as necessary.

TROUBLE SHOOTING

Note. See TROUBLE SHOOTING article in GENERAL INFORMATION section.

PRELIMINARY CHARGING SYSTEM CHECK

Ensure battery is in good condition and has a circuit voltage of at least 12.3-12.6 volts. Ensure battery connections are clean and tight. Ensure battery charging area is well ventilated and that there are no open flames or sparks. Check condition of accessory drive belt. Ensure generator connections are clean and tight. Check for parasitic drain on battery.

GENERATOR TEST

Note. Discovery Series II and Range Rover information is not available from manufacturer.

Discovery

1. Connect carbon pile rheostat according to manufacturer's instructions. Turn off all accessories. Start engine and run at 3000 RPM. Rotate carbon pile load control until greatest amperage output (minus 10 percent for EFI and ignition loss) is obtained without allowing voltage to drop below 12 volts.
2. Ensure engine is still running at 3000 RPM. Switch selector to regulator test and read voltmeter. Reading should be 13.6-14.4 volts. Switch selector to diode/stator test. Turn on headlights. With engine still running at 3000 RPM, read voltmeter. Reading must be in the "OK" range.

CHARGING SYSTEM RESISTANCE TEST

Note. Discovery Series II and Range Rover information not available from manufacturer.

1. Connect voltmeter between generator terminal B+ and positive battery terminal. (Scheme 1) Turn on headlights. Start engine. Raise engine speed to 3000 RPM and read voltmeter. Reading should be 0.5 volt or less. If voltage is as specified, go to next step. If voltage is not as specified, locate and repair high resistance in charging system circuit.
2. Move voltmeter leads to frame of generator and negative battery terminal. With engine speed at 3000 RPM, read voltmeter. Reading should be 0.25 volt or less. If voltage is as specified, charging system is okay. If voltage is not as specified, locate and repair high resistance in charging system circuit.

Scheme 1

CHARGE WARNING INDICATOR REMAINS LIT WITH ENGINE RUNNING; GENERATOR FUNCTIONS NORMALLY

Note. Discovery and Discovery Series II testing information is not available from manufacturer.

Range Rover

1. Disconnect Body Electrical Control Module (BECM) Green 20-pin connector (C1289). BECM is located under right front seat. Turn ignition switch to RUN position. Measure voltage between ground and harness connector C1289 terminal No. 15 (Brown/Yellow wire). See «WIRING DIAGRAMS»(/land-rover/discovery/l318-1998-2002/remont/charging-system/#generators-regulators). (Scheme 2)
2. If battery voltage exists, Check BECM. Check instrument cluster. See INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Repair as necessary. If battery voltage does not exist, repair Brown/Yellow wire between BECM and generator.

Scheme 2

BENCH TESTING

Note. Bench testing information is not available from manufacturer.

Removal & Installation

1. Disconnect negative battery cable. Remove viscous fan. Rotate accessory drive belt tensioner center bolt clockwise and remove accessory drive belt.
2. Remove 2 generator mounting bolts and remove generator from mounting bracket. Remove terminal cover (if equipped) and remove leads from generator terminals. Remove generator.
3. To install, reverse removal procedure. Tighten mounting nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/land-rover/discovery/l318-1998-2002/remont/charging-system/#generators-regulators__torque-specifications) .

OVERHAUL

Note. Information is not available from manufacturer.

GENERATOR SPECIFICATIONS

GENERATOR SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Charging System Wiring Diagram (Discovery). Scheme 3

Charging System Wiring Diagram (Range Rover). Scheme 4

See also:
• WIRING DIAGRAMS
• TORQUE SPECIFICATIONS