This heavy duty relay takes the heavy-amp load off the switch, thus preventing an overheated circuit and a possible wiring harness fire.
Works well with electric fans and horn circuits too. 40 amp relay.

The wiring for the relay is as follows:

• Short Red Wire (from relay post 87) = power lead to horn or fan
• Long Red Wire (from relay post 30) = main power supply in
• Short Black Wire (from relay post 85) = makes ground connection thru a temp sensitive switch or a grounding horn button
• Long Gray Wire (from relay post 86) = connects to switched 12 volt power (like ignition switch) so horn or fan turns on/off with key

Includes relay, circuit breaker, wire, terminals and instructions.