Symptoms
Damp or sagging headliner, wet carpets, electrical gremlins from a wet fuse box or climate actuators.
The fix, step by step
- Clear all four sunroof drains, then check the headliner, fuse box and blend-door actuators for water damage.
- Leaving it is what makes it expensive.
Tools & part numbers
- Trimmer line or drain-cleaning wire
- low-pressure air
- towels and patience
Where to buy the parts
Mercedes sunroof drain hoses & connectors (search; match W463 part by VIN)FCP Euro ↗
Hunting a used or discontinued part? Search eBay Motors for Mercedes-Benz G 500 parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.