Amazon.com: 5 Pack 40/30 AMP 12 V DC Waterproof Relay and Harness - Heavy Duty 12 AWG Tinned Copper Wires, 5-PIN SPDT Bosch Style Automotive Relay: Industrial & Scientific
How to wire a 5-pin Boschhorn relay - Quora
5 Pin Switch Diagram : 5 Pin Ac Motorcycle Cdi Wiring Diagram Pdf Lamberts Bikes - You can of course do both (plate mounted switch but still use the 2 extra pcb