2015-2017 Kia K900 Back Glass: Defroster Faults, Leaks, and Replacement Costs
A complete reference for diagnosing, sourcing, and understanding the replacement of the rear window on a first-generation Kia K900.
- Back glass replacement is NOT a DIY job and requires professional installation to prevent leaks and ensure safety.
- When buying used, carefully inspect the defroster grid lines and, most importantly, the soldered electrical tabs for damage.
- The primary OEM part number for the 2015-2017 Kia K900 back glass is 87110-3T000.
- A critical fire-risk recall (NHTSA 23V652) exists for the HECU unit on these vehicles; ensure this has been addressed.
Symptoms of a Failing Back Glass
Failures with the K900 back glass typically fall into three categories: electrical issues with the defroster, sealing problems causing leaks, or physical damage to the glass itself.
Defroster Not Working or Partially Working
This is one of the most common issues. You might notice your rear window isn't clearing fog or frost on a cold morning. The cause is usually an interruption in the electrical circuit. This can be due to:
- Broken Grid Lines: A scratch on the inside of the glass from cargo or improper cleaning can sever one of the thin orange or brown lines, causing that section of the grid to fail.
- Failed Defroster Tabs: The main electrical connectors, often called tabs, are soldered to the side of the grid. These can sometimes detach from the glass, cutting power to the entire system.
- Blown Fuse or Bad Relay: The defroster system uses a significant amount of power and is protected by a fuse. If the fuse blows, the system will not receive power. A faulty relay can also prevent the circuit from activating.
Water Leaks or Wind Noise
If you find moisture in your trunk, on the rear parcel shelf, or notice a musty smell, a failing back glass seal may be the culprit. Over time, the urethane adhesive that bonds the glass to the body can degrade or develop gaps, allowing water to seep in. Similarly, a bad seal can create a whistling or rushing noise from the rear of the car at highway speeds.
Physical Damage
The most obvious symptom is a crack, chip, or complete shattering of the glass. Unlike a laminated windshield, back glass is typically tempered. This means that when it breaks, it shatters into thousands of small, pebble-like pieces for safety. This can happen from an impact, or in rare cases, from extreme temperature changes or stress.
Important Vehicle Safety Recall: While not related to the back glass itself, all 2015-2017 Kia K900 models are part of a major safety recall (NHTSA ID: 23V652) for the Hydraulic Electronic Control Unit (HECU), which can short circuit and cause an engine compartment fire, even while parked. Owners are advised to park their vehicles outside and away from structures until the free recall repair is completed by a Kia dealer.
Buying a Used 2015-2017 K900 Back Glass
A used OEM back glass can be a cost-effective, high-quality alternative to a new part, but careful inspection is essential. Since this is a luxury vehicle, ensuring all integrated features work is paramount.
Visual Inspection Checklist
- Check for Scratches and Chips: Run your hand over the entire surface, inside and out. Deep scratches on the interior can damage defroster lines, and any chips or cracks compromise the glass's integrity.
- Inspect the Defroster Grid: Look very closely at each horizontal line of the defroster grid. Look for any visible breaks, scratches, or spots where the line has flaked off. A single break in a line will cause that entire line not to heat up.
- Examine the Electrical Tabs: This is critical. Locate the main electrical tabs on the sides of the glass where the wiring harness connects. Ensure they are firmly attached to the glass and the conductive material around them is intact. A detached tab is very difficult to repair reliably.
- Verify Tint and Color: OEM glass has a specific factory tint. Compare the used glass to your vehicle's other windows to ensure it matches.
- Check for Antenna Elements: Confirm that any embedded antenna wires are present and undamaged if your vehicle uses them.
Why Used OEM is a Smart Choice
For a part like this, choosing a used Original Equipment Manufacturer (OEM) part over a new aftermarket one often makes sense. The fit and finish of an OEM part are guaranteed to match factory specifications, which is crucial for proper sealing and avoiding wind noise. Furthermore, the quality of the glass and the embedded defroster/antenna elements are built to Kia's standards, ensuring compatibility and longevity.
Replacement Cost & Procedure
Replacing the back glass on a K900 is not a DIY job. It requires specialized tools to cut the old urethane seal, properly prepare the vehicle body, and set the new glass with a new bead of adhesive to ensure a safe, leak-free installation. The process typically takes a professional 2-3 hours.
Warning: Improper installation can lead to catastrophic glass failure, severe water leaks causing electrical and mold issues, and compromise the vehicle's structural integrity. This job should only be performed by a qualified auto glass technician.
| Part Type | Estimated Cost (Part Only) |
|---|---|
| New OEM | $430 - $500 |
| New Aftermarket | $250 - $450 |
| Used OEM | $150 - $300 |
| Shop Labor | $150 - $300 |
Frequently Asked Questions (FAQ)
Can I repair a broken defroster line myself?
Yes, minor breaks in a single defroster grid line can often be repaired. Auto parts stores sell special conductive paint or adhesive kits specifically for this purpose. However, if multiple lines are broken or the main electrical tab has detached, replacement of the entire glass is usually the more reliable solution.
Will my insurance cover a broken back glass?
If you have comprehensive coverage on your auto insurance policy, back glass replacement is typically covered. You will likely have to pay your deductible. Some policies have specific glass coverage with a lower or no deductible, so check with your insurance provider.
Why can't I just use silicone to fix a water leak?
Injecting silicone into the seal is a temporary, improper fix that can make a professional repair more difficult and costly later. The old urethane seal must be completely removed to address the root cause of the leak. Silicone residue prevents new urethane from bonding correctly, guaranteeing the leak will return.
Is the back glass the same for all 2015-2017 K900 trims?
For the 2015-2017 model years, the back glass is the same across the V6 and V8 trims. The key part number is 87110-3T000. Always confirm compatibility by the part number or with the seller.
Technical Specifications
OEM Part Numbers: 87110-3T000 871103T000
NAGS Part Number: FB26196GT. Features embedded defroster grid and potentially radio/GPS antenna elements.
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Kia K900: