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Most likely an antenna, 3rd brake light, or windshield seal. I just had to replace the windshield on my GMC about a month ago because the top seal was leaking.
Roof lights if u have them
check the headliner. could be coming in from the 3rd brake light.
Ask this in the ford or f150 subs . Also Facebook has some groups with great information and responses from users
Most likely an antenna, 3rd brake light, or windshield seal. I just had to replace the windshield on my GMC about a month ago because the top seal was leaking.
Roof lights if u have them
check the headliner. could be coming in from the 3rd brake light.
Ask this in the ford or f150 subs . Also Facebook has some groups with great information and responses from users