I have a 1995 D21 (second owner) in fabulous shape. I have noticed that when first entering the vehicle after it sits for a few hours there is a damp musty smell.

I can't figure out where it is coming from. I find no leaks, and no wet spots. I have removed the blower motor previously, cleaned and lubricated that. The AC system works great and does not smell musty at all.

What am I missing?

PS what is the original headliner in the D21 look like? I think I have an aftermarket.

check to see if the cowl area is clogged up with leaves and crap, also check inside the where the blower motor is and check to make sure the drain plug is not clogged. if you are positively sure its not that start pulling up the carpet and look for mold and check under the seats.

is it a common egg smell of a cab cat. The stock headliner of a HB is gray unless you have different color interior then what came with most truck. Most common is gray interior. You can also fine red and blue interior. In which case would have a matching headliner.

Pull up the carpet at the rear of the cab. Rust along the back edge of the floor can allow water to seep into the padding. If that is the cause, you will feel dampness in the padding as soon as you feel it. You cannot feel it through the carpet.
You will smell it, too.

The stock headliner has molded areas where the sun visors fold up.

-Spike

We had a very heavy rain today in atlanta, and the smell returned. I am now fairly certain that is leaking into the headliner from a questionable sealant repair in the windshield trim.

So, now the question becomes is there a preferred way to remove the original headliner (which seems ok otherwise, and to look at the windshield seal. Also, where can I purchase the chrome trim for around the windshield?

Thanks!

You may want to take it to a windshield shop and have it reglued. You might also find that you have rust issues.