The Mercedes R107 SL-Class, with its iconic design and timeless appeal, continues to captivate classic car enthusiasts worldwide. Among its engineering features is the fuel pump relay, a vital component that ensures the smooth operation of the fuel delivery system. In this article, we delve into the location of the fuel pump relay in the Mercedes R107, providing valuable insights to help owners and enthusiasts maintain and troubleshoot their beloved roadsters.
Understanding the Fuel Pump Relay’s Role
The fuel pump relay in the Mercedes R107 serves as a critical link between the fuel pump and the vehicle’s electrical system. When the ignition key is turned to the “ON” position, the fuel pump relay activates, allowing power to flow from the battery to the fuel pump. This energizes the fuel pump, which then pressurizes the fuel system, enabling the engine to start and run smoothly.
Locating the Fuel Pump Relay in the Mercedes R107
The fuel pump relay in the Mercedes R107 is typically located in the engine compartment, close to the battery or the main fuse box. While the exact location may vary slightly depending on the model year and variant, it is commonly found on the passenger’s side foot bay, attached to a relay panel:
For early R107 models (e.g., 350SL and 450SL), the fuel pump relay is often mounted on a bracket near the firewall, on the driver’s side of the engine compartment. For later models (e.g., 560SL), the relay may be positioned on the fender well or near the main fuse box:
In the later 380SL model you can find the fuel pump relay behind your glove box liner:
Troubleshooting Fuel Pump Relay Issues
In some cases, the fuel pump relay may malfunction, leading to fuel delivery problems and engine starting issues. If the engine fails to start or stalls after ignition, owners can perform basic troubleshooting to determine if the fuel pump relay is the culprit.
- Audible Click: When the ignition is turned to the “ON” position, listen for an audible click near the relay location. This click indicates that the relay is engaging and functioning correctly. If there is no click, the relay might be faulty.
- Swapping Relays: Owners can swap the fuel pump relay with another identical relay (e.g., horn relay) in the fuse box. If the fuel pump works with the swapped relay, the original relay is likely defective and requires replacement.
- Testing with a Multimeter: Using a multimeter, owners can check for voltage at the fuel pump relay’s terminals. Proper voltage readings during ignition will indicate that the relay is functioning correctly.
Seeking Professional Assistance
If owners encounter issues with the fuel pump relay or are unsure about performing troubleshooting themselves, it is advisable to seek professional assistance from experienced Mercedes mechanics or automotive technicians. These experts have the expertise and diagnostic tools to identify and resolve fuel pump relay-related problems effectively.
Conclusion
The fuel pump relay plays a crucial role in ensuring the reliable operation of the fuel delivery system in the Mercedes R107 SL-Class. Located in the engine compartment, it serves as a key link between the fuel pump and the vehicle’s electrical system. Familiarizing oneself with the fuel pump relay’s location and basic troubleshooting techniques can help owners maintain their classic roadsters and promptly address any fuel delivery issues. For more complex problems or if unsure about DIY troubleshooting, seeking the expertise of qualified professionals ensures that the Mercedes R107 continues to grace the roads with its timeless elegance and performance.
