Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
as the car has been sat for long period then its quite likely that the battery may now need replacing as they need regular charging to stay in good condition
So I'd suggest the next step is to try charging the battery up overnight with a slow charger and if that doesn't help then consider replacing the battery
Also check that the alternator is actually charging the battery in the car by taking a battery voltage reading with the engine off then another with the engine running. The 2nd reading should be higher than the 1st and climbing steadily. And also check that the alternator is secure to the engine as this provides the ground for the charging circuit and make sure that the engine / gearbox earth strap is secure and the contacts are clean and bright.
if the alternator appears not to be working - take it to a electrical specialist and ask them to test it as sometimes you can replace just the diode pack and this will repair the alternator without requiring replacement
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