Power to the gauges is keyed (part of the ignition switch). Power to the instrument lighting (orange wiring) has power at the fuse full time. The headlight switch controls that.
If you had a broken orange wire shorted to ground, it would blow the instrument lamp fuse when you turn the lights on. If you're blowing a fuse when you start the car, then theres probably a short to ground on one of the keyed circuits. Maybe even a faulty gauge is shorted to ground. You'll have to do some tracing
