'98 Ranger Anti-freeze smell?

I have a '98 Ford Ranger. WHile running/driving it smells like I have an antifreeze leak...Kind of a sweet smell in the cab...The heat blows hot, but the defrost/defog doesn't work real well. I bet it is realted. It is keeping plenty of anti-freeze so I am wondering if anyone had any ideas...Leaking heater core? Any and all advise welcome.

I had the same problem on my Ranger. It was the heater core. Brand new they are suprisingly cheap. ($17 for mine) It is a lot easier to change one than you would suspect. You do it from inside the cab, after you disconnect the heater hoses. I don't remember how many fasteners, but not many, and I had the whole job done in about 1/2 hour. If you have a manual?, check it, or just get under the dash where the heater core is and start from there. No kidding, this is a fairly easy job.