Faulty lights or indicators

A headlight that no longer lights, a light that fades at idle, indicators that won't come on or flash too fast: lighting is a safety and roadworthiness item. Most faults are electrical and accessible: a blown bulb, a blown fuse, a dead indicator relay (flasher unit), a corroded earth or terminal that cuts contact. A light that fades mainly at engine idle points rather to a weak charge (alternator/regulator) or a tired battery. Before any heavy dismantling, check the bulb, then the corresponding fuse, then the connections: it's often a matter of a few minutes. Beware of LEDs: an indicator that 'hyper-flashes' after switching to LED bulbs is due to a need for a resistor or a suitable relay, not a fault.