Alternator 1015301GD190A，ATG20865，FGN15S158 1015301GD190 for JAC T6 T8 M4 M5 M6 S7 2.0T

I. Preparation

• Tools Required: Socket wrench set (typically 10mm, 12mm, 13mm, 14mm, 17mm), open-end wrenches, box-end wrenches, screwdrivers, and a belt tensioning tool (if available).

• Vehicle Status: Ensure the vehicle is parked on level ground and the parking brake is engaged.

II. Removing the Old Generator (Installation is the reverse process)

1. Disconnect Harness: Remove the plug on the back of the generator (usually a 2-pin or 3-pin connector) and the output power cable (B+ terminal, typically secured by a nut).

2. Remove Belt: Locate the tensioner pulley. Use a wrench to rotate the tensioner to release belt tension, then remove the belt from the generator.

3. Remove Mounting Bolts: There are usually 2-3 mounting bolts (one main fixing bolt and one adjustment/pivot bolt). Once the bolts are removed, the old generator can be detached from the bracket.

III. New Generator Installation Steps

1. Positioning and Preliminary Fixing

• Place the new generator onto the engine mounting bracket.

• Insert the main fixing bolt (passing through the hole at the bottom or back of the generator) and the adjustment bolt (passing through the elongated slot at the top).

• Note: Do not fully tighten the bolts at this time. Only screw them in a few turns to ensure the generator is secure but still movable on the bracket.

2. Installing the Drive Belt

• Mount the Belt: Following the belt routing diagram (usually affixed to the inside of the engine compartment or the radiator frame), place the belt onto the crankshaft pulley, water pump pulley, tensioner pulley, and the generator pulley.

• Adjust Position: Manually pull the generator outward (away from the engine) to initially tension the belt, facilitating subsequent operations.

3. Adjusting Belt Tension (Critical Step)

• Manual Tensioning: Use a pry bar or a long wrench (taking care not to damage the housing or oil pan) to forcefully pry the generator outward to tension the belt.

• Check Tension: The tightness of the belt should be moderate.

• Standard Test Method: Press down on the belt firmly with your thumb midway between the generator pulley and the water pump pulley (or the two pulleys with the longest span). The belt deflection should be between 10mm - 15mm.

• Too tight will cause bearing wear; too loose will result in insufficient power generation or a slipping/squealing belt.

• Lock Bolts: While maintaining belt tension, first tighten the main fixing bolt, followed by the adjustment bolt. Ensure both bolts are securely tightened.

4. Connecting Electrical Wiring

• Connect Output Wire (B+): Connect the thick red power cable to the terminal marked "B+", "+", or "BAT" on the generator. Ensure the nut is tightened securely; poor contact can cause burning or power generation failure.

• Connect Plug: Insert the multi-pin connector at the back, ensuring the clip engages securely with no looseness.

IV. Post-Installation Inspection and Testing

1. Check Belt Alignment: Observe if the belt is centered on all pulleys, ensuring there is no twisting or edge lifting.

2. Clear the Area: Check the engine compartment for any leftover tools or debris.

3. Restore Power: Reconnect the negative battery cable.

4. Start-Up Test:

• Start the engine and observe if the "Charging Indicator" (usually a battery symbol) on the dashboard turns off. If the light goes out after starting, power generation is normal.

• Listen for any unusual "squealing" sounds (belt slipping) or "hissing/grinding" sounds (bearing noise) from the generator area.

• Voltage Test (Recommended): Use a multimeter to measure the voltage across the battery terminals. The voltage at idle should be between 13.5V - 14.5V. If it is below 13V, the belt may be too loose or the generator may be faulty.

• Precautions for JAC 12V Generator Installation
• Beyond the standard operational steps, "Precautions" are often the determining factor for the success of the installation and the service life of the generator.
• The following critical precautions are compiled based on the characteristics of JAC models (especially light trucks like the Shuailing, Junling, and some passenger vehicles):

• I. Core Electrical Safety (Top Priority)

• Strictly Prohibit Live-Wire Work:

• Rule: Before removing or installing any generator terminals, the negative (-) battery cable must be disconnected first.

• Consequences: If the B+ (output) wire is disconnected while the battery is connected, a wrench touching the engine metal housing will instantly create a strong short-circuit spark. This can burn the generator rectifier diodes, damage wiring harnesses, or even cause a fire.

• Strictly Prohibit "Spark" Testing:

• Rule: Never use a screwdriver to short-circuit generator terminals to test for power generation (an outdated method for older generators).

• Reason: Modern 12V generators mostly use integrated circuit regulators. Direct short-circuiting will instantly damage electronic components, rendering the new generator useless.

• Battery Polarity Must Not Be Reversed:

• Rule: When installing the battery, always ensure the positive and negative terminals are correct.

• Consequence: Reversing the polarity will immediately burn out the diodes inside the generator.

• Disconnect Load After Shutdown:

• Rule: If the vehicle is to be parked for a long period, it is recommended to disconnect the negative battery terminal.

• Reason: Some JAC models have a weak self-discharge circuit in the generator even after the engine is off, which can lead to battery drain (sulphation) during long-term storage.

• II. Mechanical Installation Details

• Belt Tension (The Golden Standard):

• Too Tight: Causes premature wear of the generator bearings (resulting in noise) and can even damage water pump bearings.

• Too Loose: Causes belt slippage, leading to insufficient charging voltage, high-temperature belt wear, and eventual breakage.

• Standard: Press the longest span of the belt (usually between the generator and water pump) with your thumb. A deflection of approximately 10mm-15mm is suitable.

• Pulley Alignment:

• Rule: After installation, a visual inspection is mandatory: check if the edges of the generator pulley, crankshaft pulley, and water pump pulley are on the same plane.

• Consequence: Misalignment causes severe side wear on the belt and can even cause the belt to jump off the track.

• Bolt Tightening Torque:

• B+ Terminal Nut: Must be tightened securely (recommended torque: 20-25Nm). If loose, high current will generate high temperatures, causing the terminal to melt.

• Mounting Bracket Bolts: Must be locked securely. If they loosen due to engine vibration, the generator housing will collide and rub against the bracket, causing the housing to crack.

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• References：
  

• The text you refer to as "JAC Vehicle 12V Generator Installation Method and Precautions" is not an excerpt from a single official or authoritative document. Instead, it is a consolidated summary based on general automotive repair specifications, technical characteristics of JAC models, and industry experience. The following is an explanation of its information sources and verification:

• I. Classification of Core Information Sources

• Source Type	Specific Content	Corresponding Text Points
  JAC Original Technical Data	JAC Vehicle Service Manuals (e.g., for Shuailing/Junling light trucks, passenger vehicle series), Engine Electrical System chapters.	Installation steps, bolt positions, belt routing diagrams, B+ terminal torque (20-25Nm), voltage parameters (13.5-14.5V).
  Industry General Specifications	Automotive Generator Repair Standards (e.g., GB/T 2820, QC/T 729), practical maintenance manuals.	Safety procedures for power disconnection, belt tension standards (10-15mm deflection), Overrunning Alternator Pulley (OAP) characteristics.
  Integrated Maintenance Experience	Common fault cases in the auto repair industry, practical operation techniques.	Ground contact cleaning, oil contamination prevention, charging indicator diagnosis, abnormal noise troubleshooting.

• II. Authoritative Tracing and Verification Methods

• 1. JAC Original Service Manuals

• Channels: After-sales service section on the JAC official website, authorized 4S store technical centers, professional automotive repair databases (e.g., ETKA, JAC diagnostic systems).

• Content: Clarifies generator model matching, mounting bracket positioning, bolt torque values, and electrical wiring specifications.

• Verification: The "Alternator Removal and Installation" chapter in the manual specifies the number of fixing bolts and tensioner operation methods for specific models (e.g., HFC4DA1 engine).

• 2. Industry Standards and Technical Documents

• GB/T 2820 "Alternating Current Generators Driven by Reciprocating Internal Combustion Engines": Specifies the output voltage range and insulation requirements for 12V generators.

• QC/T 729 "Technical Conditions for Automotive Alternators": Defines belt tension testing methods and performance verification procedures after installation.

• 3. General Maintenance Guides

• Source: Automotive repair textbooks (e.g., Automotive Electrical System Maintenance), industry platforms (e.g., Auto Repair Station, PCauto).

• Content: Covers general steps for generator disassembly and assembly, safety warnings, and electrical connection specifications. This aligns with the flow in the text: "Disconnect power → Remove wiring harness → Loosen belt → Remove bolts."