So my son is driving his '87 Camaro today when all the instruments go dead except the temp gage which pegs on the hot side. The warning horn starts to go off if the headlights are on. When he's driving with his lights on, and turns off the dash lights, the warning horn stops! Cruise control is inop too. He's in an area where the jack rabbits pack a lunch to get across, not much for shops or help. Of course he left his shop manual and electrical diagrams at home - they get messed up if he keeps them in the car

We're guessing a short behind the instrument panel, but any other ideas out there?