There’s nothing more frustrating than getting a fail on a small problem, such as nonfunctioning lights. So check they’re all working as they should. High and low beam are easy – check the tail light bulbs are working too. Indicators should flash amber, and the dash tell-tale needs to work too. Check the brake lights work on front and rear brake application – if the rear isn’t working, you may need to adjust the switch to suit the lever travel. Examine the security of connections to avoid intermittent faults. The headlight needs to be aimed correctly – a friendly tester might let you make tweaks if you can’t set it up at home. Be warned: aftermarket HID conversions are an instant fail too.