Drew,
Hook your dash lights to the tail light circuit, then go back to radio shack and ask for a variable resistor with a shaft that you can install a knob on. Insert it into the dash light wire and mount it out of site then you can adjust brightness as needed. An inexpensive fix. Some guys mount it in bottom lip of dash and most people don't notice it You probably don't need a knob if the shaft is long enough to grip with your fingers. If you happen to have an old variable speed heater switch laying around they can be used as a dimmer for your dash lights also.
