If your vehicle is showing radio, dash lights, and interior accessories randomly cut out while driving, here are the most likely causes and the parts you'll need to fix each one.
The most frequent cause of random electrical cutouts is a loose battery terminal or corroded cable, often left improperly tightened after a recent battery replacement. Bumps in the road cause momentary total power loss.
The electrical contacts inside the ignition switch wear out over time. Heavy keychains or road vibrations can cause the switch to momentarily lose connection to the accessory circuit while driving.
If the alternator is failing and not charging properly, the vehicle's voltage drops. Modern vehicles will intentionally shut down non-essential accessories like the radio and dash lights to save remaining battery power for the engine.
Relays that supply power to the interior accessories can overheat or develop pitted contacts over time. This causes them to randomly open the circuit and cut power to the dash and radio.
The BCM or main junction block controls power distribution to the interior. Internal shorts, water intrusion, or cracked solder joints can cause widespread, unpredictable accessory failures.