I am new to this site and are looking for a bit of help.....I have a 66 mustang with a 289 4speed. when i use my headlights my alternator doesn't keep up and it drains the battery, the volt meter runs around 10. If I use any other lights or stereo or anything else it is fine, up around the 13-14 mark. Could this be an alternator problem or short with my lights??? any ideas would be appreciated. thanks