Why do you blow the fuse for your dash lights and marker lights every time you turn the switch?

You have a short to ground somewhere. Start at each lamp socket, then the wiring and look for problems.

Possible bad headlight switch. Also in checking shorts, don't forget the license plate light in addition to all marker lights. Dash lights normally go out when the tail light fuse blows as dash lights are fused from the tail light circut.