Foul odor in 2015 Lincoln MKC

Foul odor coming from the interior air supply. Musty and getting worse , no moisture in cabin. Stinks, been getting worse for about a month.

Something dead in the AC air intake vent. Leaves, likely if you park outside. Rinse with water at the windshield base, pour in an anti-bacterial cleaning solution mixed with water. Let it sit overnight without rinsing. Rinse in the morning. If it knocks 1/2 the smell, do it one or 2 more times.

And change your cabin air filter.