Black soot particles from the defroster
 

Just noticed my 09 H3T Alpha has little bits of black powder like soot near the defroster vents on the dash (I've been using the defroster now since its cold and humid in NYC).

I drive mostly city right now, and since doing a cross country trip in the summer, I changed to a K&N filter. -Does the engine filter pass air onto the AC and Is it possible the K&N filter is leting in a lot of junk?

Thanks!

From what I know when I have taken apart different cars, the air filter only feeds the motor. The blower fan feeds the interior. Some vehicles have another filter in the firewall and some vehicles have the blower motor inside the cab and pull are from a vent. I will take a look at mine and get back to you. This is very interesting

Don't worry, it has nothing to do with your engine's aircleaner.

My guess is that you are parking next to a building heated with an oil burning furnace and your truck is collecting some of the soot fallout. If it's oil furnace soot, when you go to wipe it away it will leave black streaks on your dash that are a pain to clean. However, I've found that kitchen degreasers like fantastic, 409, or simple orange work the best.

If the powder is gritty, it could be from almost any source like construction work, sandblasting, or elevated trainline wheel/brake dust.