LED Light Bar Wiring Harness KC HilitesAftermarket Switch Systems Capable of powering both power modes on your Titan Light Bar when using any aftermarket switch system on either high or low power circuits. For larger length light bars (50 Inch and 57 Inch ), it is recommended to retain the majority of this wiring harness including the relay, and switch the relay on off with your aftermarket switch system. This is due to the majority of switch systems having a maximum amperage rating of