This wire tap is not a cut off but a trigger. By tapping into the high beam your giving the relay a 12v trigger to activate the lights.
This means that the lights you're installing will not work unless the high beams are on. My personal recommendation is to tie them into the parking or marker lights, this way you do not have operate the high beams in order to operate the lights on the rack. Ultimately all you are doing is giving the relay a 12v trigger to complete the circuit, the relay will handle all the juice. This 12v trigger can come from any 12v source, high beam, low beam, parking light, battery, ignition, etc. It just depends on how you want the lights to operate.
This means that the lights you're installing will not work unless the high beams are on. My personal recommendation is to tie them into the parking or marker lights, this way you do not have operate the high beams in order to operate the lights on the rack. Ultimately all you are doing is giving the relay a 12v trigger to complete the circuit, the relay will handle all the juice. This 12v trigger can come from any 12v source, high beam, low beam, parking light, battery, ignition, etc. It just depends on how you want the lights to operate.