The probe covers about 123,000 Chargers from the 2011 and 2012 model years.
The National Highway Traffic Safety Administration says it has 14 complaints of alternator failure and stalling. All the cases happened while the cars were going 40 or more miles per hour.
In one case a car stopped in traffic with smoke coming from the alternator, which generates electricity to recharge the battery and run other devices. No injuries have been reported to the agency.
Chrysler says it's co-operating in the probe. Investigations can lead to recalls but there haven't been any so far.