Your Trusted Auto Repair Shop for 40+ Years
Shop Talk Logo

What Does It Mean When My Dash Lights Flicker and Pulse?

Flickering or pulsing dash lights certainly indicate a problem with your car, but determining the exact cause is usually a job left to a mechanic with the right tools to test the electrical system of your vehicle. Generally, flickering dash lights indicate an alternator replacement, but this is often confused with a starter replacement. Learn the difference between the two parts of your vehicle to understand which is needed for which problems.

Warning Signs You Need an Alternator Replacement

The alternator is generally a maintenance-free unit, but as with any car part, it can fail. This part is responsible for charging your car’s battery when the car is running and for providing electrical power to the rest of your vehicle. Key symptoms of a bad alternator are:

  • Warning light on the dash flickers on “ALT” or “GEN”
  • Dim lights or other accessories experiencing a slowdown
  • A growling or whining noise from the engine
  • The smell of burning rubber or hot wires

A dead battery can also indicate a bad alternator, but it can also simply be a dead battery.

Today’s vehicles have built-in priority lists, which determine what order the accessories in your vehicle shut down when there is a battery or alternator problem. The radio will quit to provide more power to the lights, which lets you get somewhere safe before everything shuts down. When you notice your heated seats or phone charging system not working, it’s a good idea to have your vehicle inspected.

A mechanic has the tools to test the charging system in your car to determine where the problem lies. It could be a loose belt, faulty wiring or a blown fuse. An alternator replacement is a more expensive repair. You should make sure that the alternator is the problem before replacing it.

Signs Your Starter Needs to Be Replaced

The starter is the part which starts the ignition process in the engine. Over time, this part can wear out or break. When it happens, you will experience one or more of these symptoms:

  • The engine won’t turn over
  • You see or smell smoke when trying to start the engine
  • The starter won’t spin the motor
  • You hear a grinding noise when trying to start the motor

However, sometimes when the engine won’t turn over, it is because of a bad battery, not a bad starter. When you notice one of these problems, it is a good idea to talk to a professional mechanic to help you find the root cause. Most manufacturers do not recommend replacing the starter at a set time, because they just don’t know when one will fail.

No one enjoys having car problems, but when you have a good mechanic to help you diagnose and fix the problem quickly, you feel safer about driving your vehicle. It doesn’t take long to have an alternator system check when you have a dead battery, and it will give you peace of mind on the road.