Alternator 37300-25700 37300-2G755 37300-2G800 37300-2G850 for Hyundai Sonata/Kia Distance

Pre-installation Preparation

1. Park the vehicle on a flat surface, turn off the engine and all electrical devices. Use a wrench to disconnect the negative battery terminal. If the power will be disconnected for a long time, connect a car memory saver to prevent loss of on-board system parameters. Wait a few minutes for the capacitors to discharge to avoid short circuits caused by residual current.

2. Prepare tools such as socket wrenches, a torque wrench, and a multimeter. Ensure the new 12V alternator is compatible with the vehicle model by checking specifications including its dimensions and the number of pulley grooves. Meanwhile, inspect the new alternator for no external damage, smoothly rotating bearings, and oxidation-free wiring terminals.

Removing the Old Alternator

1. Locate the belt tensioner. Insert a properly sized wrench into the tensioner adjustment hole and rotate it in the direction that releases tension. Carefully remove the drive belt from the alternator pulley. Replace the belt if there are many cracks or severe wear.

2. First, unscrew the fixing nut of the alternator's main power cable (B+ terminal) and separate the main cable. Then press the clip of the electrical connector and gently pull it out—do not pull the wires. It is recommended to take photos to record the wiring positions for easy subsequent installation.

3. Use a socket wrench to loosen and remove the 2-3 bolts fixing the alternator. When removing the last bolt, hold the alternator by hand to prevent it from falling. Then take the old alternator out of the engine compartment.

Cleaning and Inspection

1. Wipe dust and oil from the alternator's mounting position with a clean cloth to ensure the mounting surface is flat and clean, avoiding impact on the fixing effect of the new alternator.

2. Recheck the surrounding wiring harnesses and connectors. Slightly polish oxidized terminals if necessary. Meanwhile, reconfirm the appearance and component status of the new alternator to eliminate potential issues.

Installing the New Alternator

1. Place the new alternator steadily in the mounting position, align it with the bolt holes on the bracket, and initially screw on the fixing bolts without fully tightening them to reserve adjustment space.

2. Wire according to the previously recorded positions: Firmly connect the main cable to the B+ terminal and tighten the nut. Then align the electrical connector with the clip and insert it securely. Gently pull the wires to confirm no looseness.

3. Refit the drive belt onto the alternator pulley and engine pulley. Adjust the alternator's position to ensure the belt fits properly and the two pulleys are aligned. Press the middle of the belt to adjust the tension to allow a deflection of 10-15mm. Finally, use a torque wrench to fully tighten the alternator's fixing bolts.

Post-installation Commissioning and Acceptance

1. Remove the insulation protection from the negative battery terminal, reconnect it, and tighten the nut.

2. Start the engine and use a multimeter to measure the output voltage. The normal voltage at idle should be 13.5-14.5V, and it should stabilize at 14.0-14.3V when accelerating to 2000 rpm.

3. Ensure no charging fault lights are on the instrument panel, the alternator operates without abnormal noise, and there is no excessive heat after running for a period. Turn on electrical devices such as vehicle lights and air conditioning to confirm they work normally—installation is deemed qualified once all checks pass.

Pre-installation Preparation

1. Strictly Verify Component Compatibility

   Prioritize selecting original Hyundai 12V alternators or those from authorized brands. Before installation, it is crucial to confirm that the alternator's model, dimensions, number of pulley grooves, and terminal layout match those of the original vehicle. This avoids installation failures or damage to the transmission system and electrical modules caused by mismatched specifications. Meanwhile, inspect the new alternator for no external collisions, smooth rotation of the bearing without jamming, and no oxidation or corrosion on the terminal connectors.

2. Ensure Power Disconnection and Protection Measures

   Park the vehicle on a flat surface, turn off the engine, and wait for it to cool down for more than 30 minutes. Before any operation, use a wrench to disconnect the negative terminal of the battery. If the power will be disconnected for an extended period, connect a car memory saver to prevent the loss of on-board computer parameters. It is advisable to wear safety goggles and gloves to avoid contamination from oil in the engine compartment and scratches from sharp metal edges.

3. Record Key Information in Advance

   Before disassembly, use a mobile phone to take photos of the alternator's wiring method, terminal positions, and the routing of the drive belt. Especially mark areas with complex wiring harnesses to prevent incorrect wiring or improper belt installation during reassembly.

Disassembly and Installation Process

1. Operate Gently to Avoid Damage

   When removing the old alternator, move smoothly to prevent colliding with the alternator housing, surrounding pipelines, and engine components. If the fixing bolts are rusted, spray rust remover and let it sit for 5 - 10 minutes before proceeding. Never use brute force to turn the bolts, as this may strip the bolt threads, deform the bracket, or damage the screw threads.

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References：

Professional Automotive Information Platforms

1. Autohome

   Key references are provided by the owner Q&A and maintenance-related content on this platform. For example, it mentions the need to use an OBD scanner to match parameters and calibrate the BMS (Battery Management System) module after installing a new alternator. It also emphasizes prioritizing original factory or authorized brand alternators to ensure compatibility—these points have been integrated into the relevant installation instructions.
2. Pacific Auto Encyclopedia

   The universal installation process for automotive alternators published on this platform serves as an important reference basis. Universal procedures such as disconnecting the negative battery terminal and cleaning the installation area before installation, initially securing the new alternator prior to wiring and adjusting belt tension during installation, and testing voltage after installation are all applicable to the Hyundai Elantra. Precautions from the platform, such as cleaning connectors to avoid poor contact during wiring, have also been directly adopted.

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