Expert: autohelp - 7/31/2005

Question
Having trouble with a 5.7L V8 on a 98 Chevy Silverado.  We have replaced the battery and had the alternator tested (they say it's good) but the battery is now discharged and the truck will stall a few miles after being jumped and refuse to start.  Could this be a bad ground, a bad fuse, or is there a voltage regulator or circuit board that needs to be replaced?

Answer
Sounds like you have something that is draining the battery and this needs to be tested with an AMP METER.

Maximum amperage draw when everything is off, Such as when you park the vehicle for the night is .50 amps (1/2 amp). Anything over 1 amp is to much.

The truck will naturally stall out after the battery drains out because the computer loses it pmemory of the sensor settings.

once you get the charging system fixed and drive the vehicle for about 15 miles in the city and highway the computer will re-learn and your stalling should stop.

I the battery is OK and the alternator is OK than there is a wiring problem in the charging circuit which will require some test procedures by a qualified technician.