Installation Procedure for 12V 150A Volvo Starter on Geely Coolray/Atlas Pro NL-3B (2021 Model)

Preparation Work

Tools and Accessories

Vehicle Status

Pre-disassembly of Old Component

Installation Steps

1. Positioning and Pre-installationAlign the new starter with the mounting holes on the engine flywheel housing; confirm that the drive gear meshes smoothly with the flywheel ring gear without jamming.
2. Tightening the BoltsHand-thread 2–3 mounting bolts for preliminary positioning; then use a torque wrench to tighten them in a crisscross sequence to a torque of 35–40 N·m (refer to the vehicle service manual for exact values). Avoid over-tightening to prevent bolt stripping or starter housing deformation.
3. Electrical Connection

• First, connect the thick power cable (Terminal 30) of the starter solenoid valve, tightening to a torque of approximately 9.8 N·m.

• Next, connect the thin control wire plug (Terminal 50) and ensure the lock is fully engaged.

• Finally, install terminal protective covers and wiring clips, and arrange the wires to avoid interference.

4. Reassembly and InspectionRefit all removed components such as the engine guard plate and air deflector; reconnect the negative battery cable and check that all connections are secure without looseness.
5. Function TestTurn the key to the start position and listen to the starter operation noise—the engine should start smoothly without abnormal sounds. Conduct multiple start-up tests to confirm there is no slipping or failure to start; check that the wiring harness shows no overheating and terminals have no ablation.

Precautions for Installing 12V 150A Volvo Starter on Geely Coolray/Atlas Pro NL-3B (2021 Model)

1. Mandatory Power-off RequirementDisconnect the negative battery cable throughout the entire installation process and keep the ignition switch in the OFF position. This is to prevent circuit short circuits that could burn out the starter solenoid, on-board ECU and other electronic components. Before reconnecting the negative cable, reconfirm that all wiring harness connections are correct and there are no exposed contacts.
2. Model and Compatibility VerificationBefore installation, verify the key parameters of the starter one by one: 12V rated voltage, 150A rated current, number of drive gear teeth, and mounting hole spacing. Ensure full compatibility with Volvo specifications and the flywheel housing of the Geely NL-3B model. Excessively large or small gear meshing clearance will lead to starting slippage, ring gear wear, or even starter housing rupture.
3. Precise Torque Control Execution

• Starter Mounting Bolts: Use a torque wrench to tighten them in a crisscross symmetrical sequence, with the torque strictly controlled between 35–40 N·m. Over-tightening may cause housing deformation, while under-tightening will lead to starting noise and vibration displacement.

• Electrical Terminal Fastening: Tighten the thick power cable (Terminal 30) to a torque of 9.8 N·m. Snap the thin control wire plug (Terminal 50) into the lock until it clicks into place. Do not use a wrench to forcefully tighten it to prevent terminal thread stripping or wiring harness breakage.

4. Wiring Harness Protection and Routing SpecificationsAvoid pulling or bending the wiring harness during connection. Apply a small amount of conductive paste to the terminals to reduce contact resistance and prevent oxidation and rust.After installation, use clips to secure the wiring harness to the reserved brackets on the vehicle body or engine. Ensure the harness is kept away from high-temperature engine components and rotating parts (e.g., pulleys) to avoid abrasion or scorching that could cause short circuits.
5. Meshing Condition InspectionAfter pre-installing the starter, manually rotate the crankshaft (using the crankshaft pulley bolt) to check the meshing condition between the drive gear and the flywheel ring gear. There should be no jamming or tooth butting. If meshing abnormalities are present, adjust the thickness of the starter mounting gasket or inspect the degree of ring gear wear. Do not force installation and startup.
6. Step-by-Step Functional TestingFor the initial startup, first momentarily activate the key for 1–2 seconds, listen to the starter operation sound, and proceed with normal startup only if there is no harsh noise.Do not perform consecutive startups more than 3 times, with an interval of at least 30 seconds between each attempt to prevent starter burnout due to overheating. After startup, check that the wiring harness terminals and starter housing show no signs of overheating or strange odors.
7. Component Reinstallation and ProtectionAfter completing the installation, refit all removed components such as the engine guard plate and air deflector to prevent sediment and water from entering the starter interior. For vehicles operating in dusty or humid environments, an additional starter dustproof and waterproof protective sleeve can be installed.
8. Emergency Fault HandlingIf problems such as no response during startup or gear slippage occur, prioritize troubleshooting the following items: check if the battery voltage is ≥12V, verify if the wiring harness connections are loose, and inspect whether the solenoid is faulty. Do not repeatedly force startup without identifying the root cause.

References：

Summary of General Specifications and Standards

1. OEM Documentation

• Geely: NL-3B Platform Service Manual, Parts Catalog, Fault Diagnosis Manual

• Volvo: Starter Replacement Manual, Technical Specification Sheets, Wiring Harness Installation Specifications

2. National Standards (China)

• GB/T 12732-2014 General Technical Conditions for Automotive Starters

• GB/T 5334-2008 Test Methods for Automotive Starters

• QC/T 29106-2014 Technical Conditions for Automotive Wiring Harnesses

3. International Standards

• ISO 15031-6 Safety Standard for Automotive Electrical System Maintenance

• SAE J1960 General Standard for Automotive Bolt Fastening

4. Industry Manuals

• Automotive Electrical Equipment Maintenance Manual (General Procedures for Starter Disassembly and Assembly)

• Commercial Vehicle Electrical System Maintenance Specifications (General Reference for Volvo and Geely Models)