Nu-Di Corp.'s Relay Shorting Plugs, No. 420-221, make troubleshooting common automotive electrical issues easier. This kit includes three common footprint plugs for the various relay sockets; by removing the relay in the problem circuit and replacing it with the proper Relay Shorting Plug, you instantly energize the circuit allowing for hands free trouble-shooting by narrowing the scope of potential causes. The plug is fused, and has contact points to measure for proper power draw.