Alternator 20994 849167，04E903025J，10344，20994，792535 TG14C119 04E903021R 849167，04E903025J 10344，20994，792535 FOR JETTA

The installation steps for the Jetta 12V generator are as follows: •  Preparation Work: Prepare tools such as wrenches and sockets, park the vehicle in a flat and safe place, pull the handbrake tightly, and disconnect the negative connection line of the battery.  •  Install the Generator: Install the generator on the generator bracket in front of the engine, and initially fix it with fixing bolts.  •  Install the Belt: Put the generator belt on the generator and the engine pulley, adjust the tension of the belt to an appropriate level through the adjustment slider or tensioner, and then tighten the bolts on the slider.Connecting the wires: Connect the positive wire and connector at the rear of the generator to the generator, ensuring a secure connection.  •  Inspection and debugging: Reconnect the negative wire of the battery, start the engine, and check if the generator is working properly, such as whether the charging indicator light goes off and whether the voltage is stable within the normal range (generally 13V-14V).

When installing the Jetta 12V generator, the following precautions should be noted: •  Power off in advance: Before connecting the generator, ensure that the vehicle is turned off and disconnect the negative battery cable to avoid the risk of electric shock and short circuits.  •  Ensure component matching: Confirm that the model and specifications of the generator match the vehicle, and check whether the generator's appearance is damaged. If there is damage, it should be replaced in a timely manner.  •  Clean connection parts: Before wiring, use sandpaper or a special cleaning agent to clean the oxide layer, oil stains, and dust on the terminals and connection parts to ensure good electrical contact and prevent abnormal power generation caused by poor contact.Pay attention to the wiring sequence and method: First, connect the battery cable to the "B+" terminal of the generator, then connect the other end to the positive pole of the battery; then connect the excitation wire to the "D+" or "F" terminal and to the charge indicator light or regulator; finally, connect the ground wire to the ground terminal and to the vehicle's metal parts. Be careful not to connect the wires incorrectly, as this may damage the generator or other electrical equipment.  •  Secure the bolts and circuits properly: When installing the generator's fixing bolts, tighten them to the specified torque to ensure the generator is firmly installed. At the same time, check the fixing of the circuits to avoid loose or shaking wires and prevent potential short circuits.  •  Adjust the belt tension: When installing the belt, adjust its tension properly. If the belt is too loose, it will easily slip, resulting in insufficient power generation; if the belt is too tight, it will easily damage the belt and the generator bearings.  •  Test after installation: After installation, reconnect the negative pole of the battery, start the vehicle, observe whether the charge indicator light on the instrument panel turns off normally, and use a multimeter to measure the voltage across the battery. When the engine is running, the voltage should be between 13.8V and 14.5V to ensure the generator is working properly.

References：The content you provided regarding the installation precautions for the Jetta 12V generator does not have a clear single source. It is compiled by integrating information from multiple authoritative sources related to automotive maintenance. Some of the content is consistent with relevant articles on PCauto. For example, the article "What are the Types and Characteristics of Alternator Grounding?" mentions that attention should be paid to aligning the center of the pulley groove and the tightness of the belt when installing an alternator. The article "What are the Detailed Steps and Key Precautions for Connecting a Car Generator?" states that before connecting the generator, the negative pole of the battery should be disconnected, the terminals should be cleaned, and after connection, the fixing and insulation of the circuits should be checked, among other things.At the same time, several articles on Autohome also cover similar content. For example, "How to Correctly Install a Car Alternator" mentions that before installation, it is necessary to confirm that the alternator matches the vehicle model, and after installation, a voltage test should be conducted, among other things. "What Are the Steps and Precautions for Alternator Wiring?" mentions that attention should be paid to the order and firmness when wiring, etc.