98 Dakota truck cap interior light

Ground one wire of the light. connect the other to a good 12v constant positve source.

If you don't feel competent enough to tap into a wire in your vehicle, you could just run the wire directly to the + terminal of the battery.

But please, please wherever you make your power connection, use a fuse and place it close as possible to the power source for safety. a 25 cent fuse is pretty cheap insurance compared to burning something up.

As for ground it is completely unnessecary to run it all the way to the battery. if anything this will add resistance, heat and possibly a dimmer light.

You want to find a metal surface to bolt or screw the wire to. If the mounting surface for the ground is painted or otherwise coated, srcape the area down to bare metal (about the size of a dime should do), crimp on a small ring terminal, screw or bolt it in (an exsiting screw or bolt can work as well if its a ground point,) and the job is done.

Good Luck.