Impact switch is on the passenger side inner wing, near the base of the windscreen, red rubber cap. If it's been triggered you can reset it by simply pressing the button (top face of rubber cap), you'll feel it click with little pressure. If that's down, test the terminals for resistance - if there's no/very low resistance you know the switch isn't the issue.
Check each point on the power supply route for power, if there's an issue with the wiring you'll find a point where everything downstream is dead, so work forwards from there.
Check each point on the power supply route for power, if there's an issue with the wiring you'll find a point where everything downstream is dead, so work forwards from there.