Tail lights flickering over bumps.

[RotaryRocketeer]

So, either my tail lights or brake lights are flickering when I go over bumps in the road. Seeing how my truck is a one ton, everything in the road is a bump. These are not factory brake/tails. They're the units from SuperBrightLED for flatbeds/trailers.

I didn't know anything about it until my buddy mentioned it while following me the other day. Who knows how long it's been going on but, now that I know, it's annoying the hell out of me. All other electrical systems operating normally. Any tips on where to look first? All help and suggestions appreciated.