okay, i have a 2000 chevy s10, it has a brand new battery and alternator. When the battery is charged the battery meter will keep dropping until the dash is completley off when im driving, then i wont be able to start it unless i get a jump or charge the battery. why is the battery draining so quickly?
It’s possible your new alternator is defective. Automotive or non-automotve, I can’t tell you how many times I bought items that did not work properly.
Check and see if the fusible link in the large wire that runs from the alternator to the battery is burned.
Tester
Make sure that the battery warning light turns on when you turn the ignition switch to ON. Current has to pass through the warning lamp to the L lead of the alternator in order to supply power to the exciter circuit inside the alternator. If that is okay, the connections to alternator are good and the fuses to those circuits are okay then it appears the alternator is bad. You can have it tested at places like Autozone.
Get a digital voltmeter to plug into a 12V socket and you’ll know immediately when the battery isn’t charging. (Pull the meter when you stop if not turned off by the ignition switch.)