All lights dim as turn signal is engage

[92sc300]

Has anyone encounter the problem that all the interior lights and head lights blink when you use the turn signal, brake or power in the car? When I use the turn signal, my headlights and speedometer lights also dim as the signal blinking. They also go dim as I apply the break pedal or use the power window. I took my SC 300 to local repair shop and they don't know what the problem is. Does anyone knows what the problem is? It is very annoying when I drive at night. Please advice if anyone encounter this problem.

[92bonny]

Bad alternator and possibly a bad battery. Have both checked at a respectable dealer or repair shop.