1979 Chevrolet Truck Chevy Scottsdale battery keeps dying

Are you sure the battery is good? You can use a digital multimeter across battery posts, the generic spec for a full charge is around 12.6 volts. If the battery is down, take it off and get it charged. You shouldn't let the alternator charge a down battery.

With a full charge, start the vehicle, take second reading across across battery posts, the second reading should be higher than the first, if charging system is ok.

As far as battery drain, with key off, the old way to test, was take battery cable loose, use a testlite between cable and battery post, if lite came on bright, you have a drain. Make sure no lites on anywhere, under the hood, interior, anywhere. As far as lites, the best time to check is in the dark.

If no lites on anywhere, then you pull/replace fuses one at a time, when you pull the fuse on a problem circuit, the lite goes out, then you check everything on that fuse circuit.

Sometimes a faulty alternator can drain battery, but the alternator is new, correct?

What model of chevy truck do you have? I'll try to look up headlamp wiring? I already told you how to check for battery drain. The alternator bat terminal, with the key off, any voltage? Unless you can do a little testing, I'm not sure how to help?

Mt bad it's a scottsdale.

As far the headlamps, I'd have to check voltage to and from the headlamp switch. Then through the dimmer switch.

Did you check for voltage and ground at the headlamp connector? The tan wire and lt green are voltage for high beam and low beam. Black wire is ground.

Headlamp switch gets voltage through red wire, hot all the time from fusible link. From the headlamp switch lt blue wire carries voltage to dimmer switch. From dimmer switch to head lamp, lite green wire is voltage for bright. Tan wire is voltage for low beam. Use a test lite to check for voltage.