A valid question.

There are a few sources inside the cabin. The factory radio wires, for example, in the console. Various screws off the headlight switch if you're looking for something on that side. I've posted the wires for both of those locations recently. <>

If you can find a wiring diagram pins marked "15" a commonly switched.

Consider consumption the fuse size when tapping off a line.

There should be no trouble finding one in the fuse box. Turn the box over and you ought to have the fuse list.

As always with 25 year old electrics - trust but verify with a meter.