If your vehicle is showing dashboard lights flicker over bumps, here are the most likely causes and the parts you'll need to fix each one.
The battery terminals or cables are loose or heavily corroded. Hitting a bump causes a momentary loss of electrical connection to the entire vehicle, making the dash lights flicker or the engine stumble.
A fuse or relay that powers the dashboard or body control module is not fully seated in the fuse box. Bumps cause it to wiggle and momentarily break the circuit.
The electrical contacts inside the ignition switch are worn out. Physical shock from bumps causes the heavy key chain or the switch internals to shift, briefly cutting power to the dashboard.
The main electrical connector behind the gauge panel is loose, or the instrument panel bulbs are not seated correctly. This often happens after recent dashboard or aftermarket radio work.
Internal components in the alternator or its voltage regulator are failing or have loose connections. Bumps cause momentary voltage drops that dim or flicker the lights.
The computer that controls interior electronics has an internal short, a loose ground wire, or a failing solder joint that reacts to physical vibration.