Why do the dashboard lights go off on a 1995 Grand Prix when headlights are turned on?

When you turn on the headlight switch, you are turning on 2 circuits. The headlights are on one circuit and the other circuit is the tail lights and the dash lights. The tail lights are on a separate fuse and the dash lights feed off that circuit with usually a 5 amp fuse also. Sometimes when the dash lights don't work, the dash light fuse is blown. Sometimes the tail light fuse blows and it feeds 12v to the dash fuse. Also a bad headlight switch can cause the dash (and or tail lights), not to work also.

Do you see two green arrows and no dash lights?. A loose ground clip is the suspect and a real pain to fix. A hard slap with the palm of your hand on the hump forward of the steering wheel has turned the lights on every time I have tried it.

You must know all of the bulbs will never burn out at the same time also the fuse controls several other things including those two green arrows.