Instrument Panel Lights Flickering and Exterior Lights Intermittent on GMC Sierra 3500

The headlight switch used on the GMC Sierra 3500 is known to fail through normal operation. Since the headlight switch is also integrated into the interior lights, a malfunctioning switch can cause issues with interior lights as well.

• Symptoms of a failed headlight switch include:
• Headlights and taillights failing to turn on or off
• Interior lights flicker, or fail to turn on or off
• Gauge cluster lighting off or flickering with headlights on
• Parking light malfunctions

This issue is well known with General Motors Trucks and SUVs, and is solved by testing and, if needed, replacing the headlight/dimmer switch. Bad grounding wires at the tail-lights, and dirty/corroded tow package wires can also lead to some of these issues.