The installation of Mitsubishi 12V automotive generator shall be carried out on the premise of power-off, following the procedures of positioning and fixing, belt assembly, circuit connection, commissioning and testing. The core requirements are to standardize the torque and belt tension, and ensure correct electrical connections. The following is a universal installation method applicable to mainstream Mitsubishi models, including key precautions and references to authoritative sources.
Positioning and Preliminary FixingPlace the generator into the mounting position in the engine compartment, align it with the bracket holes, insert the fixing bolts and adjusting bolts, do not tighten them temporarily to leave room for adjustment.Tighten the base fixing bolts to a torque of 20–25 N·m, and pre-tighten the adjusting bolts first (torque varies with different models, subject to the maintenance manual).
Drive Belt Assembly and Tension AdjustmentInstall the belt onto the pulleys according to the specified routing direction, and adjust the generator position via the adjusting bolts to tension the belt.Tension Standard: Press the middle part of the belt with fingers; the deflection should be about 5–10 mm. When tested with a tension gauge, the tension for mainstream models is generally 400–600 N (specific value subject to the vehicle model manual).Lock the adjusting bolts, recheck the belt tension, and then tighten all fixing bolts to the standard torque.
Electrical Circuit ConnectionTerminal Definition (Common for Mitsubishi Generators): Terminal B (+) is connected to the positive terminal of the battery (with a fuse installed); Terminal F (field) is connected to the regulator; Terminal N (neutral point) is connected to the charging indicator light; Terminal E (-) is connected to the vehicle body ground.First connect the cable to Terminal B, then plug in the regulator connector, field wire and signal wire. Ensure that all terminals are firmly clamped without loosening, and reset the protective sleeves.
Reset and Basic CommissioningReinstall the removed components such as air intake hoses and splash shields, and reconnect the negative terminal of the battery.Power on and check the charging indicator light (it should turn off after engine startup, indicating normal operation); start the engine and use a multimeter to measure the voltage at Terminal B. The voltage at idle speed should be approximately 13.5–14.8 V, without significant fluctuations under load.
Finalization and Record-keepingRecheck the belt tension, bolt torque and circuit connections; clear fault codes, restore the settings of radio and other equipment, and record the installation time and component models.
Power-off Operation as PriorityThe negative terminal cable of the battery must be disconnected throughout the installation process to prevent short circuits that could burn out the generator regulator or on-board electronic control unit (ECU). Reconnect the negative terminal only after the installation is completed to avoid electric arcs caused by live-wire connection.
Precise Torque Control
The tightening torque for the generator fixing bolts shall be 20–25 N·m. Loose bolts will lead to generator vibration and belt misalignment, while over-tightening may cause thread slipping of the bracket or cracking of the generator housing.
The tightening torque for the cable terminal of Terminal B (positive terminal) shall be 15–20 N·m. A factory-standard fuse (80–120 A) must be installed, and direct connection with bare wires is strictly prohibited.
Standardization of Belt Tension and Routing
The belt must be installed strictly in accordance with the routing direction specified in the factory diagram. Incorrect routing or reverse installation is forbidden. Adjust the belt tension to the level where pressing the middle part of the belt with fingers results in a deflection of 5–10 mm, or a tension value of 400–600 N measured by a belt tension gauge.
The old belt must be replaced simultaneously if cracks, delamination or aging are found. Insufficient tension will reduce power generation efficiency, while excessive tension will accelerate the wear of generator bearings and water pump bearings.
Error-proofing and Anti-loosening for Electrical Connections
Strictly follow the terminal definitions: Terminal B is connected to the positive terminal of the battery, Terminal F to the regulator, Terminal N to the charging indicator light, and Terminal E to the vehicle body ground. Reverse connection (especially between Terminal B and Terminal E) is strictly prohibited, as it will directly burn out the generator.
Connectors and wiring terminals must be firmly clamped in place and equipped with insulating sleeves. The wire diameter of the grounding wire for Terminal E shall not be less than 6 mm² to ensure reliable grounding and avoid voltage fluctuations caused by loose connections.
Compatibility and Adaptability Check
Verify that the generator model is fully compatible with the vehicle model. For models with built-in regulators, check the communication protocol between the regulator and the on-board ECU to prevent malfunctions such as constant on or off of the charging indicator light.
Before installation, inspect the generator stator and rotor for short circuits or open circuits, and check the rectifier diodes for proper functionality to prevent quality issues with new components.
Key Points for Commissioning and Re-inspection
After starting the engine, observe the charging indicator light: it should turn off automatically at idle speed. A constantly lit or flashing indicator light indicates abnormalities in the circuit or regulator.
Use a multimeter to measure the voltage at Terminal B. The normal voltage at idle speed is 13.5–14.8 V. If the voltage is lower than 13 V or higher than 15 V, stop the engine immediately to troubleshoot the fault.
After installation, recheck the status of all bolts, connectors and belts to ensure there is no looseness or interference, and clear the fault codes of the on-board system caused by power-off.
Requirements for Safety Protection and Working Environment
Wear insulating gloves and goggles during operation to prevent oil stains from contaminating the generator terminals. No foreign objects such as tools or gaskets shall be left in the engine compartment to avoid being drawn into the pulley during operation.
It is forbidden to plug or unplug circuit connectors or touch the terminals with metal tools while the generator is running, to prevent electric shock or short circuit.
References：
The core sources of the "Precautions for Installation" of Mitsubishi 12V generator are divided into three parts: official authoritative documents, industry standards and content integration instructions, which are detailed as follows:
The above precautions are generalized summaries based on Mitsubishi official data. For model-specific parameters (e.g., torque values, belt models), refer to the corresponding vehicle maintenance manual, as the general values are for reference only.
Key data (such as the bolt torque of 20–25 N·m and the Terminal B voltage of 13.5–14.8V) are compiled from the parameter ranges specified in the maintenance manuals of mainstream Mitsubishi models, rather than direct excerpts from a single document. It is necessary to verify the data against the specific vehicle model.
The terminal definitions (B/F/N/E) follow the universal labeling standards for Mitsubishi automotive generators. For some new models equipped with built-in regulators, the wiring may be simplified, and the actual wiring shall be subject to the vehicle’s wire harness connector configuration.
