I have been reading a lot of posts and have gotten some good ideas of what the problem might be with my 98 Dakota, but I am having a hard time deciding where to start. I just bought this truck, and when I turn on the air vents I get a bad smell coming out, it kind of smells musty, it doesn't matter if I have the air or heat on, either way I get the bad smell coming out. The air orginally worked but after a couple days it stopped, I'm guessing the dealer filled it up to sell it and it must have a leak or something. Also, I noticed the heat barley works, you can put the heat on full blast and it blows out warm air but not warm enough to heat the truck.

Can it be the heater core making the smell even though it still smells with the a/c on? Or could it be the a/c drainage tube even though it still smells with the heat on?

Any information would be greatly appreciated!

 

sounds like your heater core. is your passenger side floor wet?

 

the smell is just mold in the air tubes and/or condensation drains. the little drain tube in the firewall could be stopped up - locate it and poke it out with a pencil, wire, or wire tie. a simple remedy for the smell is to use a spray can of Lysol Fresh Linen Scent, roll down windows, turn on defroster or vent, and spray a liberal amount into the passenger side cowl. you'll see it getting sucked in.