Truck headlamp casings are designed to be strong; however, these covers can suffer from road damage. If a stone flies up when you're driving and hits one of your lamps, then it often cracks the casing. The crack might not look too alarming at first. Your headlamp's cover might still be intact. However, you should replace the headlamp as soon as you can. Why?
Your Headlamp Bulb Might Stop Working
If a crack in your truck's headlamp goes all the way through its glass or plastic cover, then the headlamp loses its ability to shield its bulb. If your lamp isn't intact, then you might run into problems if rain or water from the road gets through the crack.
For example, if moisture gets inside the headlamp, then it might steam up the cover. Condensation will build up inside when the moisture hits the heat of the bulb.
If your headlamp mists over, then it becomes obscured and cloudy. Light might not shine out as brightly as it usually does.
If your headlamp is too dim, then other drivers will have problems seeing you on the road at night. They might not see you indicate to turn, and you could cause an accident.
In some cases, incoming water or moisture can blow a headlamp bulb. If the bulb is hot because you've been using it recently and it gets hit by cold water, then the bulb could short or even pop into pieces.
In this case, you'll be left with only one working headlamp. Again, this makes your truck more of a safety hazard on the road. Plus, traffic police might pull you over and give you a fine if you only have one working headlamp.
You Might Damage Key Circuits
If you're lucky, a crack in your headlamp might not get worse or it might not affect your bulb. However, you could have other damage going on behind the scenes that you don't notice.
For example, if the inside of your headlamp gets wet or damp, then the connections that wire the headlamp to your truck could get corroded and damaged. You won't just have to pay to replace the headlamp if this happens, but you could also end up with a heftier bill to replace wires and terminals.
So, an early replacement makes safety and financial sense. To get the best replacement kit, buy a manufacturer-compatible product. For example, if you crack a Scania left-hand headlamp, you should find a supplier that sells these lights.