Once we realized how important it was to be inspecting our  bikes and vehicles in order to pay  attention to what it was telling us, we made up a little routine of things to look at before going for a ride.
 Checking over the lighting is one of them. It’s important to make sure  turn signals, brake and headlights are all working before  starting to interact with traffic. So check all your lighting to make sure all’s good.  If you have a burnt bulb your owners and service manual will have a part number listed for replacement.  Using the shop manual is what makes self-maintaining your machines possible.  Change any bulbs that are burnt out. You might find that your brake light is not working but your bulb is good.  If thats the case, the next place to check is the brake switches. The front brake switch is in the handlebar controls (on a motorcycle) and the rear is a switch wired into the rear brake line. Eliminate which is not working, front or rear brake switch and re-place the switch.
The part number for your model will be listed in your parts book. If you don’t have a parts book the salesman at the parts counter can hook you up if you have your model and year handy.  If you have a horn on your bike you might as well take advantage of it and make sure it’s working. It’s nice to have the option to blast a warning to one of those idiots creeping out of a drive-way that for sure doesn’t see you, go ahead and blast the horn to give them a heads up  your out there. The horn works well for that.  It takes just a few seconds to make sure all the lighting on your bike/vechicle is working properly, so be sure to take the time to do it.