What to Do If the Rear Window Defroster Grid is Broken?
2 Answers
If the rear window defroster grid is broken, it cannot be repaired and must be replaced. The function of the heating wires on the rear window is: during rainy, snowy, or foggy weather, when the defrost and defog control switch is turned on, the resistance wires heat up upon receiving electricity, raising the temperature of the glass. The frost or fog attached to the glass melts from the heat, turning into water droplets that flow down or evaporate as mist, thereby achieving the effect of removing frost and fog. This allows the driver to clearly discern the traffic conditions behind and perform safe operations such as reversing. The defrosting and defogging of the front windshield are controlled by another switch. If the rear window defroster switch is frequently turned on, the heating wires on the front windshield are also working. However, if there is no freezing or even frost in the front windshield wiper area at this time, it can be commonly understood that this part of the glass is being dry-heated. Over time, the glass in this area will inevitably become abnormally fragile, and cracks may appear with slight external force.
My car's rear windshield defroster also failed once, which happened on a winter morning when thick frost made it dangerously hard to see behind. First, don't panic - as a temporary solution, you can manually remove the frost using an ice scraper or soft cloth to ensure driving safety. Most defroster failures are caused by blown fuses or poor wiring connections, so I recommend first checking if the corresponding fuse in the fuse box has blown; if so, try replacing it with a new one. If that doesn't work, you may need to inspect the wiring or the defroster grid itself, as oxidation or breakage could be the issue. This isn't something to delay, as it affects rear visibility when reversing, especially during rainy or cold weather. I suggest getting it checked at a proper repair shop as soon as possible to prevent minor issues from becoming major problems. For prevention, have technicians inspect the electrical system during regular maintenance to avoid future troubles. Also, be careful not to let objects press against the rear window during normal use, and keeping it clean can help extend its lifespan.
