Installation Method for Mitsubishi 12V Generator

I. Preparation Work and Safety Specifications

1. Park the vehicle on a flat surface, engage the parking brake, shift to P/N gear, and turn off the ignition switch.

2. Disconnect the negative battery cable and secure it properly to prevent accidental grounding; record electronic data such as the radio anti-theft code and clock settings.

3. Prepare tools: socket wrenches (10–19mm), torque wrench, belt tension gauge, flathead/Phillips screwdrivers, insulated gloves, and safety goggles.

4. Check that the model of the new generator matches the old one; verify that the regulator, pulley, and wiring terminals are intact. It is recommended to replace the belt and tensioner pulley as a set during generator replacement.

II. Detailed Installation Steps (Universal Procedure)

1. Generator Positioning and Preliminary Installation

1. Place the generator into the mounting bracket on the engine side, insert the fixing bolts and adjustment bolts, do not fully tighten them initially to leave room for position adjustment.

2. Tighten the main fixing bolts to the model-specific torque: generally 20–25N·m (e.g., for the 6G72 engine), refer to the service manual for exact values.

3. Install the adjustment bracket/rod to ensure the generator can move freely for belt tension adjustment.

2. Electrical Connection (Critical Error Prevention)

• Connect the B+ terminal first, then plug in the signal connector to avoid short circuits during operation.

• Apply conductive paste to all wiring terminals to prevent oxidation; pull gently on the connections after tightening to verify they are secure.

3. Belt Installation and Tension Adjustment

1. Route the belt over the generator pulley, crankshaft pulley, tensioner pulley, and other pulleys in accordance with the engine belt routing diagram. Ensure there is no misalignment or twisting of the belt in the pulley grooves.

2. Adjust the belt tension:

• Manual adjustment type: Loosen the generator adjustment bolt, use a pry bar to gently lever the generator outward to tension the belt, then retighten the adjustment bolt and recheck the tension.

• Automatic tensioner type: Press the tensioner down to the lowest position, install the belt, then release the tensioner to allow it to automatically return to the tensioned position.

3. Tension standards: Press the middle of a new belt—deflection should be 5–8mm; for a used belt (with less than 5,000km of service), deflection should be 8–12mm. Alternatively, use a belt tension gauge to calibrate according to model-specific parameters (e.g., typical Mitsubishi values range from 450–550N).

4. Manually rotate the pulley before starting the engine to confirm there is no binding or abnormal noise.

4. Fastening and Power Restoration

1. Retighten all fixing bolts and adjustment nuts to the specified torque using a torque wrench to prevent loosening.

2. Remove all tools and debris from the engine compartment, then reconnect the negative battery cable.

3. Restore electronic settings such as the clock and radio anti-theft code.

5. Functional Testing

1. Start the engine and let it idle—the charging indicator light on the instrument panel should turn off. Use a multimeter to measure the voltage at the B+ terminal: a normal reading is 13.8–14.8V at idle (not less than 13.2V under load).

2. Increase the engine speed to 2,000rpm—the voltage should remain stable with no significant fluctuations. Check that the belt shows no signs of slipping or abnormal noise.

3. Turn on high-load accessories such as the air conditioner and headlights—the voltage should remain within 13.5–14.5V to confirm the charging system is functioning properly.

Key Precautions for Installation of Mitsubishi 12V Generator

I. Safe Operation Precautions

Priority to Power-off Operation

1. The negative battery cable must be disconnected before installation, and the cable end shall be fixed away from the negative terminal to prevent accidental grounding and short circuit.

2. It is prohibited to plug or unplug the generator wiring harness connector or tighten the B+ terminal nut without powering off, so as to avoid instantaneous overvoltage damaging electronic components such as the vehicle ECU and regulator.

3. Before reconnecting the negative terminal, it is necessary to confirm that all tools and debris are away from the engine compartment to prevent them from being drawn into the pulley after startup.

Wearing of Protective Equipment

1. Insulated gloves and safety goggles shall be worn during operation to prevent electric arc burns caused by short circuit of metal tools, or coolant and engine oil splashing into the eyes.

2. When disassembling or installing the belt, it is forbidden to directly touch the working surface of the pulley with hands to avoid being pinched by rotating parts.

Vehicle Parking Specifications

1. The vehicle shall be parked on a flat and firm ground, the parking brake shall be pulled up, and the gear shall be shifted to P (for automatic transmission) or 1st gear (for manual transmission) to prevent the vehicle from sliding during installation.

2. If the vehicle needs to be lifted, a formal lift or jack + safety bracket must be used; it is prohibited to carry out operation only supported by a jack.

II. Installation Precision Precautions

Strict Compliance with Torque Requirements

1. Torque of the main fixing bolt of the generator: 20–25N·m (applicable to mainstream engines such as 6G72 and 4B11; refer to the vehicle maintenance manual for specific values). Insufficient torque will cause the generator to loosen due to vibration, while excessive torque will damage the threads of the mounting bracket or the generator housing.

2. Torque of the B+ terminal nut: 8–12N·m, which shall be tightened with a torque wrench. It is strictly prohibited to tighten it violently with an adjustable wrench to prevent terminal thread slipping or insulation dust cover cracking.

3. Torque of the adjusting bolt/rod nut: 15–18N·m. After tightening, it is necessary to ensure that there is no displacement clearance of the generator.

4. References：
   

5. The content is sorted by authority priority as follows:

6. I. Core Authoritative Sources (Official Technical Documents)

7. 1. Original Factory Service Manuals for Various Mitsubishi Vehicle Models

8. Scope of Application: Covering mainstream Mitsubishi models such as the Pajero (equipped with 6G72 engine), Outlander (equipped with 4B11 engine) and ASX, corresponding to the chapter "Charging System / Alternator Installation".

9. Key Basis: Torque values such as 20–25N·m for the main fixing bolt of the generator and 8–12N·m for the B+ terminal nut, definitions and wiring specifications of B+/IG/L/E terminals, as well as belt routing and tension parameters, are all derived from the Standard Operating Procedures (SOP) in the manuals.

10. Example Manual Numbers: Such as the 6G72 Engine Service Manual, the Electrical System Chapter of the 4B11 Engine Service Manual (relevant technical documents with Mitsubishi original part numbers such as MR599381).

11. 2. Mitsubishi Motors Official Technical Bulletins / Service Information

12. Key Content Points: Safety operation specifications for generator installation (e.g., power-off to prevent ECU damage, recording of radio anti-theft codes), recommendations for simultaneous replacement of belts and tensioners, etc. Issued by the technical department of Mitsubishi Motors, these documents are used by 4S stores and authorized maintenance stations to implement unified standards.

13. II. Industry and National Standards (Compliance Basis)

14. QC/T 729-2005 Technical Specifications for Automobile Alternators: Specifies basic requirements for generator installation such as electrical safety, terminal connection and insulation protection, including standards for B+ terminal insulation protection and grounding conductivity testing.

15. GB/T 18420.2-2001 Automotive Maintenance Terminology - Part 2: Body Maintenance: Provides general safety specifications and terminology definitions for installation operations, such as torque control and belt tension testing methods.

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