LEDs (light-emitting diodes) are everywhere these days, in mobile phones, TVs, cars and motorhomes. But what exactly are they? Although widely accepted as an upgrade, are there any downsides to fitting LEDs in your motorhome? LEDs are diodes, belonging to the semiconductor family. Semiconductors conduct current and insulate, both at the same time. LEDs only work one way, so if wired back to front, they will not illuminate – reversing connections on LEDs allows them to light up.