One of the most troublesome problem that you can have in a car is when your headlights stop working things can get very dangerous in a big hurry. But headlights can also fail in the other direction. Far from a fail safe, headlights that won't turn off, no matter what you do, can quickly drain your battery and leave you stranded. If you don’t have time to tackle the problem right away, or you just want to be able to leave the car for a while without the battery dying, there are two different ways to keep the headlights from killing the battery. One of the easiest way to keep the battery from dying is to disconnect it. This involves literally disconnecting one of the battery cables from the battery, which requires an appropriately sized wrench or socket. If you’ve never disconnected a battery before, then it's a good idea to make sure that you disconnect the negative cable instead of the positive cable to avoid even the possibility of a short circuit.
Reasons behinds Headlights to Stay On can be that the system may have failed, and you might want to try shutting the headlights off before turning the engine off to see if that helps.
It can also happen that swapping relays doesn't work, your problem may be a bad headlight switch, multi function switch, or light sensor, and the diagnostic procedure will be more complex.
The reason can be a bad headlight switch that's shorted internally may get hot enough to crack, melt, or even burn the plastic housing or electrical connections, but that isn't always the case.
These are some of the most common reasons that might be behind the light failure.