You can buy a mechanical one, instead of electrical. Pesonally, I like them better anyways. If you get one with an LED backlight, LED can run on DC or AC current. Just hook the power wire to your headlight switch, so the light comes on with the headlights. These are some good ones. I think they come with peanut bulbs, but you can buy LED peanut bulbs for a couple bucks. Well known brand, for half the price. And, looks much better.
http://store.summitracing.com/partdetail.a...mp;autoview=sku
http://store.summitracing.com/partdetail.a...mp;autoview=sku