The battery gauge in a vehicle will move when you use your power mirrors as your causing a small drain on the battery & lowering the voltage slightly.
The effect is normally only really visible when the engine is not running.
These will be the coolant temperature gauge, oil pressure gauge, and battery voltage gauge.
brakes, lights, oil, water, battery, air & gas
Is vehicle actually overheating ? and Is it charging? Many of this early Optimas have grounding issues that can cause the temp gauge to read higher than normal
Yes, because your vehicle will overheat.
Either your battery is dead, or your alternator has failed.
There is probably a dead short in the system.
Possible bad alternator.
there is no transmission gauge on a vehicle.
Having a short in the turn signal wiring can cause gauges to fluctuate. If the battery gauge is fluctuating corrosion on the cables can be a possible cause.
What year is your car? Did you mean the CHECK ENGINE light? The battery gauge?
Its a sign that either your battery or alternator is starting to fail.
it works in side the battery