car dies with light on.

[ghosttownboy]

I am a new owener of a 1972 spider 850 with 58000 o. miles. it runs great, but then i turn on the head light it slowle dies. it was in storage for some years, could the light switch be bad??? of something in the wireing?? any help . it took a half hour to die and would noy start again, until i jumped it and died again when i bturned the lights back on.

[So Cal Mark]

you're going to need a voltmeter, but it could be as simple as loose battery cables. It sounds like the alternator is not working but the first step is to check cables for clean, tight connections