This is my Folks car. They are 80 and 75 so I don't want it leaving them stranded. Last time this occurred the mechanic replaced the battery and starter, did voltage drop tests, said problem was fixed. Folks took a long drive yesterday and parked the car in their driveway. Went out to move car into garage and car was so dead it had no dome light, elect locks wouldn't click. Any suggestions?

. I suspect the alternator is bad--likely the voltage regulator/brush holder assembly, which is easy to replace. Perform the simple regulated battery voltage test in the link below:

https://www.askmehelpdesk.com/cars-t...ml#post1973613

If it's less than 14 volts, replace the alternator. Be sure to remove and fully charge the battery, prior to installing a new alternator. Otherwise, you may burn out the new alternator. Most auto parts stores will charge batteries for free.


. Here's how to change the alternator, if they have the Duratec engine:

https://www.askmehelpdesk.com/cars-t...ml#post1375856


. Here's how to rebuild the alternator yourself, if you are looking for a fun project:

https://www.askmehelpdesk.com/cars-t...ml#post2518522


. If the problem persists, read the link below on parasitic battery drain:

https://www.askmehelpdesk.com/cars-t...tml#post241804