Run power from battery to a relay that is energized by a power source that is only on during time bike is on. Most kits come with a relay that is supposed to be powered from the high beam power wire so lights come on when high beam is on.
Negative wire goes from battery to lights. Positive wire runs to relay and then to lights. Small power source (high beam) runs to relay to power it when you want lights on.
Make sure there is a fuse coming off the battery on the positive power wire.
Flickering to me would be a loose wire or connection.
Below is a typical PIAA set up
And an explanation how a relay works. Sorry, I am not an artist or an engineer so it is not done beautify OR to perfection!
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