Just bought a 00 civic ex and having a problem with the alternator and battery both are new but it still keeps boggling out on me as if I ran out of gas if I keep it on a jump box it runs fine but 10 mins after unplugging it I’ll notice my rpm drop straight to 0 and my radio goes out alternator is a 97 integra 90v could it be that I need to use a civic si alternator or a wire is loose? Checked the grounds and they’re good so just clueless at this point any help?

 

Multimeter. Check for battery voltage at the alternator with the car off. If you have none, check the charging circuit wiring. If you have voltage with engine off, alternator could be bad and bench testing will be best. Most local auto stores will test it for free just bring it in.