Alternator 6678560，AVA0122，6678560，400-40019 40040019，A002655302 11736，425303 6678560，AVA0122 6678560，400-40019 FOR BOBCAT

Bobcat 12V Generator Installation Method

Safety & Preparation 

1. Disconnect Power: Disconnect the negative (-) battery cable and place a warning sign.

2. Secure the Machine: If necessary, raise the cab/lift arm and support it with a jack and stand to stabilize the machine.

3. Tools and Consumables: Gather tools such as sockets, wrenches, a belt tension tool, a torque wrench, cleaning supplies, and rags. Consumables include thread locker, electrical tape or heat shrink, and grease.

4. New Generator: Ensure the new generator matches the original machine's model, power output, and mounting dimensions.

5. Mark and Photograph: Document the location of electrical connectors, belt routing, and mounting bolts to avoid rework.

Removing the Old Generator (If Necessary)

1. Loosen the Belt: Release the tensioner or adjustment bracket and remove the belt, noting its routing.

2. Disconnect Electrical Connections: Disconnect the main power cable (B+), followed by the connector/field wire, and label each connection. Ensure terminals are insulated.

3. Remove Mounting Hardware: Unscrew the adjustment and mounting bolts, then carefully remove the old generator. Clean the mounting surface of oil, dirt, and corrosion.

Installing the New Generator (Standard Procedure)

1. Clean and Prepare: Clean the mounting surface, bracket, and bolt holes. Apply a thin, even layer of grease to the new generator's bearings and shaft journals. Verify the pulley orientation and keyway alignment.

2. Position and Secure: Place the generator in its mounting location and hand-tighten the bolts. Use the specified torque from the service manual to tighten the mounting and adjustment bolts. (Thread locker is recommended.)

3. Install and Tension the Belt: Route the new belt according to the original diagram. Use the tensioner or adjustment bracket to set the tension (pressing the center of the belt should deflect it by 10–15 mm, with no slippage or abnormal noise). Lock the tensioner in place and recheck.

4. Route and Insulate Wiring: Connect the connector/field wire first, then secure the B+ cable (using a lock washer). Insulate all terminals and route wires away from hot components and moving parts.

5. Power On and Test: Reconnect the positive (+) battery cable. Start the engine and measure the output voltage at idle or medium RPM. A normal voltage range is 13.8–14.5 V. Check for abnormal noises, overheating, or belt slippage. Recheck torque and tension if necessary.

Key Points for Common Models (Bobcat Skid-Steers/Loaders)

• Models 753/763/863, etc.: Typically require removing the cab/lift arm. Disconnect the red B+ cable and electrical connector, loosen the adjustment bolt to remove the belt, install the new generator with correct torque, tension the belt, and test the voltage (13.8–14.5 V).

• Built-in Regulator: Connect B+ to the battery positive or main fuse, and connect the field wire to the ignition switch or dashboard.

• Diesel Models: Ensure the generator pulley is aligned with the crankshaft pulley to prevent belt wear. Check belt tension when the engine is cold and recheck after it has warmed up.

Common Troubleshooting

• No Output/Low Voltage: Check for loose B+ connections, open or faulty field wires, belt slippage, regulator failure, or internal generator issues. Re-test voltage and check wire continuity.

• Abnormal Noise/Overheating: Check for misaligned pulleys, worn bearings, incorrect belt tension (too tight/loose), or an uneven mounting surface. Realign and retension the belt, or replace damaged components.

• Charging Light Remains On: Check for an open field circuit, poor connector contact, or internal generator failure. Inspect wires and connectors, and replace the generator if necessary for testing.

Bobcat 12V Generator Installation Notes

I. Safety 操作规程 (Operating Procedures)

1. Power Disconnect: Before removing and installing, always disconnect the negative (-) battery cable to prevent short circuits and electric shock hazards.

2. Work Area Safety: Ensure the work area is clean and free of obstacles to avoid tripping or collisions.

3. Hot Components: Generators can become very hot during operation. Avoid direct contact to prevent burns.

4. Rotating Components: Be cautious of rotating parts such as the generator pulley during installation and removal to prevent entanglement or pinching injuries.

II. Pre-Installation Preparation

1. Model Compatibility:

• Critical: The new generator's model, power output, mounting dimensions, belt type, and connector definition must match the original machine precisely.

• Verification: Cross-check the generator part number (e.g., Bobcat OEM number) to ensure it matches the recommended model in the service manual.

2. Tools Preparation:

• Gather specialized tools such as a torque wrench, sockets, and a belt tension tool.

• Prepare cleaning supplies and rags for cleaning the mounting surfaces.

• Prepare consumables like thread locker (for securing bolts), grease (for bearings), electrical tape, and heat shrink.

3. Component Inspection:

• Inspect the new generator for physical damage, such as cracks or deformation.

• Inspect the generator belt for cracks, wear, aging, or looseness.

III. Installation Process Key Points

1. Cleaning and Lubrication:

• Thoroughly clean the generator mounting surface, bracket, and bolt holes to remove oil, dirt, and corrosion.

• Apply a thin, even layer of grease to the new generator's bearings and shaft journals.

2. Precise Positioning:

• Align the generator accurately with the mounting holes to ensure a tight fit of the mounting surfaces.

• Verify that the orientation of the generator pulley and the crankshaft pulley, along with their keyways, are correctly aligned.

3. Proper Securing:

• Hand-tighten the mounting and adjustment bolts first to achieve initial positioning.

• Tighten all bolts to the specified torque values from the service manual, especially the mounting and adjustment bolts. Never use excessive or insufficient torque, as this can lead to bolt loosening, breakage, or mounting surface deformation.

• It is recommended to apply thread locker to the bolts to enhance their anti-loosening effect.

4. Belt Installation and Tensioning:

• Route the new belt strictly according to the original diagram to avoid premature wear or breakage due to incorrect routing.

• Correctly adjust the belt tension: When pressed in the middle, the belt should deflect by 10–15 mm. Excessively tight tension will cause premature bearing wear, while insufficient tension will lead to belt slippage and insufficient power generation.

• After installation, manually rotate the pulleys to check if the belt rotates freely and does not deviate significantly.

5. Electrical Connections:

• Wiring Order: Connect the connector/field wire first, then secure the B+ main power cable. Ensure all connections are firm and free of looseness.

• B+ Cable: The B+ main power cable should be connected to the battery positive terminal or the main fuse. Ensure a reliable connection and use a lock washer.

• Ground Cable: The ground cable should be connected to a reliable ground point such as the engine block to ensure good electrical ground.

• Insulation: All wire terminals should be properly insulated and routed away from hot components and moving parts to prevent abrasion and short circuits.

6. References：

• Content Source: The content integrates standard disassembly and assembly procedures for general automotive/construction machinery generators (alternators), maintenance experience for mainstream Bobcat models (such as 753/763/863/S160/T190, etc.), industry-standard parameters (voltage test threshold: 13.8–14.5 V; belt tension specification: 10–15 mm deflection), and basic safety operating requirements.

• Official Reference: For official sources, it is recommended to consult the corresponding Bobcat factory service manual (Service Manual). It contains precise part numbers, bolt torques, wiring diagrams, and installation steps, which are the most authoritative references.

• If needed, I can help you find the corresponding Bobcat factory manual link or part number based on the specific model (e.g., S160, T190, 753) for cross-verification.