headlight drain

have any of you had any problems with your headlights draining too many volts out of the battery? it seems that my voltmeter drops almost 2 volts when i turn the headlights on. i have already had the battery drain so that i couldn't crank the engine. i've put a new battery in, but the headlights still drain the same. if any of you have any possible solutions besides testing every wire, i'd be very happy to hear them. thank you
Don