1998 Pontiac Bonneville runs fine until you come to stop light

mmctighe

1998 pontiac bonneville car runs fine until you come to stop light then tach drops down to 500 also

my problem its acting like its having hard time holding rpm too 1000 and voltage drops to 8 volts. sometimes i have to power brake until computer reset itself to 1000 rpm. any advise would be helpful

elias

the battery is discharged and probably ruined. alternator is likely failed, and/or the voltage-regulator. these things are fairly easy to test - most shops will do the test for free.

mmctighe

my alternator shows 13.8 and then voltage drops when let off throttle to come to stop sign. Then its momentary fighting to hold idle. Thank you for your help. sad too say hard to guess without a scanner