What Mike said
it seems that many times, if you read between the lines of mikes and my post, the ambulance on many fire departments is where they put people who they don't want to be FF's or who are in trouble.
If you don't fit the list above and you just want to be a medic and not really a fire fighter, then let them know that when you get hired, but NOT before you get hired, and I'm sure you will get put on a medic unit. you will still get the title FF/EMT-P but just not the experience putting out the fires.
But if you want both worlds, then don't tell em you want to only be a medic.
But in all honesty, many places in the U.S. you gotta do both to make the good money and have advancement. That's just the name of the game. Sucks if you aren't really interested in being a smoke eater but you do what you have to do to feed your family and put a roof over your head.