Q: Car keeps dying while i drive. I have a brand new battery and just replaced the alternator a week ago. Dies when headlights are on

Although the alternator is new, and presumably working properly, charging system output should still be measured at the battery terminals. You want to rule out a problem in the charging circuit and/or connections to the battery. If charging system output is normal, the amount of current drawn by major circuits running off the battery should be measured. It is possible there is a high resistance somewhere, a bad ground, or a "phantom" electrical load that is not supposed to be there and that can cause a voltage drop, possibly explaining the issue your car is experiencing. To have all the appropriate diagnostic tests performed, the service to request is an electrical circuit/component diagnostic. If you request that, the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.