Tonight after idling for a few minutes my battery light came on. It would go off when the engine RPM rose to about 1,000 or above, then come back on when RPM dropped to idle. Battery connections appeared to be good. (Will check that again in the morning and also battery voltage.) Drove the car around the block and the speedo and tach started jumping around then completely died. Dash lights and headlights were dim. Got back, put the car in park, got out and opened the garage door, then car would not shift out of park. Had to manually disengage the shift interlock. Then it seemed the transmission would not engage correctly; barely got back into the garage.

The battery was replaced less than two years ago and the alternator less than a year ago.

Hoping to get an idea what might be going on before I have to drop it off with my mechanic next week.

 

check the alternator belt and have the battery and alternator tested. check all power connections and grounds.

 

Internal voltage regulator on alternator crapped out. Replaced alternator and battery.