Sunroof leaks dominate complaints on the 2006 H3. Water pours into the cabin during rain at highway speeds and when parked, soaking carpets, floorboards, and the driver's seat. Dealers treat clogged drain lines as the cause and blow them out, but the problem returns within months. Some owners describe drain tubes as undersized by design. Water intrusion causes mold, mildew smell, and damage to electrical systems. In severe cases, the entire interior required stripping and drying, though one dealer offered only a credit toward a future vehicle purchase.
Blower motor resistors and wiring harnesses fail repeatedly, causing burning smells, visible smoke from vents, and complete heating/AC loss. Owners report melted connectors and connectors that fail again after replacement. An independent mechanic charged $300 ($170 labor, $130 parts) for resistor replacement.
Windshields break easily from road debris—one owner had two replacements within two weeks—because the vertical windshield angle does not deflect impacts. A hood louver detached at highway speed and cracked another windshield.
In 2015, GM issued Campaign 15V421000 to address HVAC and visibility issues, but critical parts remained unavailable for months or years. Multiple owners received recall notices but could not get repairs, and the manufacturer delayed beyond reasonable timeframes.
Failure modes owners describe
Sunroof water leaks and drain clogging
Sunroof seals and drain lines fail or clog repeatedly, allowing rainwater to flood the cabin, damaging interior trim, carpeting, and electronics. Owners report water running down faces, soaking floorboards front and back, and dealers repeatedly blowing out drains as a temporary fix. Some owners describe drain lines as undersized by design.
When: 30,000 to 196,000 miles; recurring issue throughout ownership
Symptoms owners cite: Water leaking from sunroof into cabin during or after rain; Clogged sunroof drain lines; Mold growth and mildew smell inside vehicle; Water pooling in floorboards and behind glove box; Mold and water damage to carpeting, electrical systems, and flooring
Repairs/costs cited: Dealers unclog drains as temporary measure; some replace sunroof seals; retrofitting drain lines done at owner expense ($100 unpaid diagnostic charge noted); full vehicle interior stripping, treating, and drying required in severe cases
Recalls/TSBs owners mention: Warranty coverage on first occurrence; after expiration, charged $100 for diagnosis; manufacturer offered credit toward future purchase in one case; NHTSA Campaign 15V421000 recall parts unavailable
Windshield impact fragility and damage
Windshields break easily from road debris and rock impacts, with vertical windshield proportion allowing objects to strike and shatter without deflection. Two replacements occurred within two weeks on one vehicle.
When: Occurred within two-week period; highway and local area driving
Symptoms owners cite: Windshield cracking and breaking from highway debris and rocks; Repeated windshield failure within short time frame; Vision obstruction from cracks; Hood louver detaching and cracking windshield
Repairs/costs cited: Windshield replacement performed; no design correction noted
Blower motor resistor and wiring harness failure with burning
Heater and A/C blower motors fail due to burned-out resistor and melted wiring harness. Owners report smoke, burning odors, and melting vents. Failures recur after repair on same vehicle. One owner reports connector module failure causing similar symptoms.
When: 68,000 to 147,000+ miles; recurring failures after repair
Symptoms owners cite: Blower motor failure; heater and A/C inoperative; Burning odor from vents; White or visible smoke from vents during operation; Melted wiring harness and resistor; Abnormal noise from vents; Vents melting; carpet burning
Repairs/costs cited: Blower motor resistor and resistor wire harness replacement; R&R labor and parts cited at $300 ($170 labor, $130 parts) by independent mechanic; connector module replacement performed in one case; repairs recur
Recalls/TSBs owners mention: NHTSA Campaign 15V421000 recall parts unavailable; manufacturer exceeded reasonable repair time; one owner case where heater failed after recall repair was performed
HVAC system intermittent failure and inoperability
Heating and air conditioning systems fail to activate, operate intermittently without warning, or stop working altogether. Defroster malfunction creates safety hazard in cold or foggy conditions.
When: 40,000 to 147,000+ miles; intermittent and recurring
Symptoms owners cite: A/C and heater fail to function when activated; Intermittent operation at various speeds; Defroster failure in cold or foggy conditions; Vent controls fail to function; Abnormal noise and odor from vents
Repairs/costs cited: A/C unit needed freon in one case but not repaired; repairs not completed in multiple cases; recalls parts unavailable
Recalls/TSBs owners mention: NHTSA Campaign 15V421000 recall parts unavailable; manufacturer exceeded reasonable repair time
Fan relay burnout and electrical smoke
Fan relay burned during operation, creating visible smoke inside vehicle. Owner disconnected relay as temporary fix.
When: 115,000 miles
Symptoms owners cite: Visible smoke inside vehicle from behind dashboard; Fan relay burned
Repairs/costs cited: Owner disconnected relay; not professionally repaired
Recalls/TSBs owners mention: NHTSA Campaign 15V421000 recall parts unavailable; manufacturer exceeded reasonable repair time
Sunroof drain clogging from dirt accumulation
Dirt from air becomes clogged in sunroof, affecting sunroof operation and causing water leaks during rain. Water leakage affects main vehicle computer performance.
When: 196,000 miles; recurring throughout ownership
Symptoms owners cite: Dirt clogging in sunroof; Water leaking into vehicle when it rains; Main vehicle computer affected by water intrusion; Recurring vehicle performance issues
Repairs/costs cited: No repairs noted
Instrument panel gauges difficult to read
Gauges on instrument panel are difficult to read; contributes to visibility classification in recall.
When: Unknown mileage
Symptoms owners cite: Gauges on instrument panel difficult to read; All gauges and meters providing incorrect readings (in one case due to water damage)
Repairs/costs cited: No repairs noted
Recalls/TSBs owners mention: NHTSA Campaign 15V421000 recall parts unavailable
NHTSA Campaign 15V421000 recall parts distribution failure
Multiple owners received recall notifications for Campaign 15V421000 (Visibility) but repair parts remained unavailable for extended periods, some without experiencing actual failure. Manufacturer exceeded reasonable repair timeline.
When: Recall issued; parts unavailable; 2015-2016 complaint timeline
Symptoms owners cite: Recall notification issued but parts unavailable; Manufacturer exceeded reasonable repair time
Repairs/costs cited: Recall remedy unavailable; parts distribution disconnect documented by VIN tool
Recalls/TSBs owners mention: NHTSA Campaign 15V421000 recall parts unavailable; manufacturer made aware of delays and parts unavailability
Synthesized from 42 NHTSA owner complaints — unverified consumer
allegations, summarized for patterns. The verbatim filings appear below.