Generator TG12C037 AV6N-10300-HA AV6N10300HA 1685794 1469714 7G9N10300CA is suitable for Ford Fiesta

Pre - installation Preparation

1. Verify Accessory Compatibility

   Prioritize the use of original Ford or authorized 12V alternators. Check the mounting hole spacing, pulley diameter and terminal definitions of the alternator to ensure full compatibility with the vehicle's year and engine model, so as to avoid compatibility issues.

2. Prepare Tools and Protective Gear

   Get tools ready including a socket wrench, torque wrench, belt tensioner, multimeter, OBD scanner, cleaning cloth, and thread locker (optional). Meanwhile, wear gloves to prevent scratches from oil stains or high - temperature components during operation.

3. Cut Off Power for Safety

   Disconnect the negative cable of the car battery and keep the cable end away from metal parts to prevent short circuits caused by tools touching the terminals during operation. If the power cut lasts for a long time, a memory saver can be used to protect the settings of the on - board system.

Remove the Old Alternator

1. Take Off the Drive Belt

   Use a wrench or a special tool to loosen the belt tensioner, and take the alternator belt off the pulley. It is advisable to take a photo to record the belt routing to avoid mistakes during reinstallation later.

2. Disconnect the Circuit Connections

   Unplug the wire connector at the rear of the alternator or unscrew the fixing nuts of the terminals to disconnect all circuits. Mark the connection position of each wire with a label to prevent confusion.

3. Remove the Old Alternator

   Use tools to loosen and remove the alternator's fixing bolts (usually 2 - 3 bolts), and gently take out the old alternator. Then use a cleaning cloth to wipe off dust, oil stains and rust on the engine's mounting surface, so as to ensure that the new alternator fits tightly during installation and reduce vibration - induced damage.

Install the New Alternator

1. Temporarily Fasten the Alternator Body

   Place the new alternator stably in alignment with the holes on the mounting bracket. Install the fixing bolts and tighten them initially without fully securing them, leaving room for adjusting the belt tension afterward.

2. Install and Adjust the Belt

   Put the belt on according to the previously recorded routing and adjust its tightness via the tensioner. Press the middle of the belt; the deflection should be controlled between 25mm and 38mm. A loose belt tends to slip and affect power generation, while an overly tight one will accelerate the wear of bearings and the belt.

3. Firmly Tighten the Body Bolts

   Use a torque wrench to tighten the fixing bolts to the specified torque (28 - 32N・m is recommended for most Ford models). A small amount of thread locker can be applied to prevent loosening, avoiding bolt loosening due to vibration when the vehicle is running.

Conduct Standardized Wiring

1. Wire According to the Marks

   Connect the thick charging wire to the "B+" or "+" terminal of the alternator, and the thin field wire to the "F" terminal or the "IGN" terminal on the ignition switch side. Make connections strictly in accordance with the previous marks and never reverse them.

2. Ensure Good Terminal Contact

   Clean rust and oxide layers off the terminals. Fully insert the connectors or tighten the fixing nuts to prevent unstable power generation caused by poor contact. It is recommended that the charging wire be of 10AWG or larger gauge. In addition, route the wire away from high - temperature areas such as the exhaust pipe to prevent melting of the wire's insulation layer.

Commissioning and Final Inspection

1. Preliminary Power - on Test

   Reconnect the negative battery cable, start the engine and let it run at idle speed for 3 - 5 minutes. Listen for abnormal noises such as bearing squeaks and belt slipping from the alternator.

2. Test Voltage and Calibrate

   Use a multimeter to measure the output voltage of the alternator. The normal voltage range is 13.5 - 14.5V. If the voltage is lower than 13.5V or higher than 15V, turn off the engine immediately to check the wiring or belt tension. For Ford models equipped with an intelligent charging system, connect an OBD scanner to the vehicle to complete alternator initialization and BMS calibration, ensuring that the system can recognize the charging status.

3. Recheck and Finalize

   After turning off the engine, recheck whether the fixing bolts and wiring of the alternator are loose. Arrange the wires properly to avoid entanglement. Then take a short test drive. The installation is completed when no fault lights are on the instrument panel and the voltage remains stable during the test drive.

Safety Operation Red Lines

• Disconnect the negative battery cable first and never reconnect it until installation and wiring are fully completed. This prevents short circuits caused by tools touching terminals, which could burn out the generator or battery.

• Do not touch the positive and negative terminals of the generator simultaneously with metal tools. Keep away from rotating pulleys and high-temperature engine components (such as the exhaust pipe) during operation, and always wear gloves for protection.

• For models equipped with an intelligent charging system, do not operate under high load for a long time before completing BMS calibration to avoid system errors or charging logic disorders.

Installation Precision Requirements

• The new generator must be fully compatible with the Ford model and engine type. Never force installation if there is a mismatch in mounting hole spacing, pulley diameter, or terminal definitions—this could lead to failure in securing the generator or transmission malfunction.

• Tighten the fixing bolts to the specified torque of 28-32N・m. A small amount of thread locker can be applied for anti-loosening to prevent bolt loosening and generator displacement due to vibration during vehicle operation.

• Strictly control belt tension: Press the middle of the belt, and the deflection should be controlled between 25-38mm. An overly loose belt may slip and affect power generation, while an overly tight belt will accelerate the wear of generator bearings and the belt itself, shortening their service life.

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References：

Overseas Automotive Parts and Maintenance Websites

1. vintageautogarage.com

   This website provides multiple installation instructions for Ford - series alternators. For instance, the installation steps for the wiring connector of the Ford G3 alternator mention key points such as disconnecting the battery before disassembly and assembly, selecting 10 - gauge or 8 - gauge wires for the charging cable, and testing the voltage to be between 14.1V and 14.6V after installation. Additionally, the installation guide for the 12V negative - ground conversion of the Ford Model A clearly specifies essentials like adjusting the belt tightness and following standard alternator wiring procedures. These contents are highly consistent with the core requirements in the installation precautions, including electrical safety through power disconnection, standardized wiring, and voltage testing.

2. americanmuscle.com

   The alternator installation tutorial for specific Ford Mustang models published on this website elaborates on operations such as disconnecting the negative battery terminal, removing the belt tensioner, and the sequence for disassembling and installing the fixing bolts. It provides model - specific practical basis for the content related to the disassembly and assembly process and component protection in the installation precautions.

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