Q: Alternator bad? 2002 Ford Escape

Hello - something is not right with your alternator. Unless the serpentine belt is loose (worn belt or loose tensioner) and slipping, the voltage regulator should keep the alternator charging at 14.5 volts or higher as the engine revs. It should not exceed 15 volts, but shouldn’t be dropping down to 12 volts either. I would have the alternator checked/replaced by the auto parts store that sold it to you - I think the voltage regulator is malfunctioning (the voltage regulator is an internal component to modern alternators). For assistance with this repair, I recommend a alternator replacement performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.