Is there a voltage regulator in a 1975 cadillac sedan deville The battery is new but won't charge The alternator is in good condition and looks like new Could it be a bad alternator?

Answer 1

The voltage regulator is built into the alternator. If you have used your vehicle to jump start another vehicle, even if it is the first time your auto has been started since the alternator was replace you risk blowing the new alternator. Always make sure that when connecting jumper cables that the red is connected to the positive of both autos and the black is connected to any metallic ground on the engine NOT the negative of the your battery. When the dead engine starts and the alternator fields are flashed in the dead car it causes a voltage spike that will eventually blow a good alternator. You might get by with it many times, but the law of averages will catch up with. Not IF but WHEN! Once you start you auto use a voltage tester and touch the battery cable ends, not the battery posts. You should get a reading of 13 volts or more. If not either the battery is defective or there is a short somewhere else. If you do not have a voltage tester just start the engine and disconnect one lead from the battery. If the engine dies the alternator is bad. A good battery should read no less than 10.89volts when fully discharged. If it reads less the battery is defective. A fully charged good battery should read 12.5 volts or slightly more.