643 Automotive Relay (4-Pack) 12V 30A 4-Pin SPST - OE Replacement for 8K0951253 - Compatible with Audi A4 A5 A6 Q5 Q7, VW Golf Jetta Passat - for Fuel Pump, Horn & ECM Power

Professional Electrical System Maintenance for European VehiclesMaintaining the electrical integrity of your vehicle requires components that meet specific engineering standards. The 643 Relay (Part Number 8K0951253) is a cornerstone of the power distribution system in many Audi and Volkswagen models. This 4-pack of 12V 30A relays offers a standardized solution for replacing aged or sticking relays that cause intermittent stalling or failure to start.Engineering and Material ScienceOur relays are housed in PA66-GF30 reinforced nylon, a material selected for its high melting point and structural rigidity under the extreme temperatures of an engine compartment. Inside, each unit features silver-alloy contacts for consistent conductivity and an internal resistor designed to suppress back-EMF, helping to shield your vehicle's Electronic Control Unit (ECU) from potential damage during switching cycles.Versatile Application and Diagnostic SupportWhether you are diagnosing a P0230 fuel pump circuit fault or refreshing the cooling fan control module, these SPST relays provide reliable switching power. They are also suitable for aftermarket electrical additions under 30A, provided they are installed in a water-resistant enclosure as per standard automotive practice.Installation Considerations:Verification: Confirm the "643" print or the 8K0951253 part number on your existing relay before replacement.Procedure: Always ensure the ignition is off and, ideally, the battery is disconnected when servicing the relay panel to prevent accidental short circuits.System Integrity: Replacing multiple relays simultaneously can ensure uniform electrical resistance across linked systems, such as dual-speed fan circuits.Important Compatibility Check:While the 643 relay is standard for the 2009-2016 Audi A4 (B8/B8.5 platform), some regional variants may use different relay configurations. Please visually compare the pin layout on the bottom of your current relay with our product images to ensure a 100% match before ordering.

• [VERIFIED FIT FOR AUDI/VW] Precision-engineered as a direct replacement for part #8K0951253. Fully compatible with Audi A4 (2009-2016), Q5, Q7, and VW Jetta/Golf models. Please match the "643" number and the 4-pin diagram on your old relay before purchasing
• [RELIABLE POSITIVE-LOCK CONTACT] Featuring thickened alloy terminals designed to provide the necessary "click" and tactile feedback when seated. This ensures a low-resistance connection to the ECU, preventing the loose contact issues common with thin-pin aftermarket relays
• [SURGE PROTECTION TECHNOLOGY] Integrated with a built-in suppression resistor. This technical feature absorbs inductive voltage spikes when the relay switches off, shielding your vehicle’s computer systems from damage and electrical noise
• [EXTREME ENVIRONMENT READY] The PA66-GF30 glass-fiber reinforced housing is built to withstand the intense heat and vibration of the Audi/VW engine bay, ensuring the internal silver-alloy contacts won't stick or fail over time
• [COST-EFFECTIVE MAINTENANCE] This 4-pack allows you to refresh multiple aging relays simultaneously (e.g., Fuel Pump + ECM + Fan), ensuring consistent electrical resistance across your vehicle's power distribution network