Q&A

 Master

I would not say it is entirely abnormal - the power window motors especially will draw a decent amount of power from the vehicle to operate, and this draw can dim the lights. The lock buttons do not draw as much power, but still draw some nonetheless. If you feel it's abnormal, you can have your battery and alternator checked. Poor battery capacity and/or low charging voltage from the alternator/voltage regulator (internal to the alternator assembly) could allow excessive dimming as a result. On a load, you want to make sure you are no lower than say... 13.8 and probably be above 14 volts. The battery should have a full state of charge and be in the mid to high 12's voltage-wise. On a load, the battery should not drop below the mid 10's in voltage. You may also want to lubricate the glass runs and weatherstripping on the doors as dry glass runs cause glass to bind going up and down...and binding glass is harder to move...which means the power window motors have to work harder...drawing more voltage and causing greater dimming (and slower operating windows too!). Lubing your door glass runs regularly is good preventive maintenance for window motors. Good luck.