Wire the Relay

• 1). Connect the negative side of the relay coil to ground.
  
  
• 2). Connect the positive side of the relay coil to the switch that will operate your accessory.
  
  
• 3). Connect the common (C) terminal of the relay to the battery source that will provide power to your accessory.
  
  
• 4). Connect the normally open (NO) terminal to the power input of the accessory the relay will operate.