Well, lets start with the easiest place first. Look at your battery connections to make sure they are clean and connected. You shouldn't be able to turn either cable. If that is ok, move to the box next to the battery, and take the lid off and look at all those connections next. Connections should be clear of corrosion, and solidly connected. Next would be the fuse box on the other side of the engine bay. Look at all connections, and fuses for corrosion or being loose. Definitely electrical. It could be in behind the dash, lets hope not. That is a lot more lookin' and work. Good points on the previous posts too..