MTC 4809 Auxiliary Fan Control Relay Instruction Manual

1. Introduction

This manual provides essential information for the installation, operation, and maintenance of the MTC 4809 Auxiliary Fan Control Relay. This component is designed as a direct replacement for OEM part number 357-919-506A, ensuring proper function of your vehicle's auxiliary cooling fan system.

2. Product Overview

The MTC 4809 is an automotive relay responsible for controlling the auxiliary cooling fan. It operates automatically to regulate engine temperature by engaging the fan when necessary. This unit is built to meet original equipment specifications for reliable performance.

Figure 1: MTC 4809 Auxiliary Fan Control Relay, showing the main body and electrical connections.

Figure 2: Close-up view of the MTC 4809 relay, highlighting the integrated fuse compartment and terminals.

Figure 3: Bottom view of the MTC 4809 relay, illustrating the multi-pin electrical connectors for vehicle integration.

3. Compatibility

The MTC 4809 Auxiliary Fan Control Relay is compatible with the following Volkswagen vehicle models:

• VW Golf: 1995-1999
• VW Jetta: 1994-1999
• VW Passat: 1995-1997

This relay is a direct replacement for OEM part number 357-919-506A.

4. Installation

Installation of the MTC 4809 Auxiliary Fan Control Relay should be performed by a qualified technician or an individual with appropriate automotive repair experience. Always ensure the vehicle's battery is disconnected before beginning any electrical work.

1. Locate the existing auxiliary fan control relay in your vehicle. Refer to your vehicle's service manual for the exact location.
2. Carefully disconnect the electrical connectors from the old relay.
3. Remove the old relay from its mounting bracket.
4. Install the new MTC 4809 relay into the mounting bracket.
5. Connect the electrical connectors to the new relay, ensuring they are securely seated.
6. Important Note: A N0171252 fuse may be required upon installation. Verify your vehicle's specific requirements and replace the fuse if necessary.
7. Reconnect the vehicle's battery.
8. Test the auxiliary fan operation to ensure proper function.

5. Operation

The MTC 4809 Auxiliary Fan Control Relay operates automatically. When the engine coolant temperature reaches a predetermined level, or when the air conditioning system requires additional cooling, the relay will activate the auxiliary cooling fan. This process helps maintain optimal engine operating temperature and ensures efficient air conditioning performance.

6. Maintenance

The MTC 4809 Auxiliary Fan Control Relay is designed for long-term, maintenance-free operation. Regular vehicle maintenance, including checking electrical connections for corrosion and ensuring proper fuse integrity, will help ensure the longevity and reliable performance of the relay.

7. Troubleshooting

If the auxiliary cooling fan is not operating correctly after installation, consider the following troubleshooting steps:

• Check Fuse: Verify that the N0171252 fuse (if applicable) and any other relevant fuses in the vehicle's fuse box are intact and not blown.
• Electrical Connections: Ensure all electrical connectors to the relay are clean, secure, and free from corrosion.
• Fan Motor: Confirm that the auxiliary fan motor itself is functional. This may require direct testing of the fan motor.
• Temperature Sensor: A faulty engine coolant temperature sensor can prevent the fan from activating. Consider testing or replacing the sensor if other checks yield no results.
• Professional Diagnosis: If the issue persists, it is recommended to seek diagnosis from a certified automotive technician.

8. Specifications

9. Warranty Information

This MTC 4809 Auxiliary Fan Control Relay is a warranty-backed item. For specific details regarding warranty coverage, duration, and claims procedures, please refer to the documentation provided at the time of purchase or contact MTC customer support directly.

10. Support

For technical assistance, installation questions, or warranty inquiries, please contact MTC customer support through their official website or the contact information provided with your product packaging. When contacting support, please have your product model number (4809) and purchase details readily available.