I got a 97' Neon w/ 99k on it. Last week I lost my heater and got nothing but cold air. When I got off work I topped off the fluids, that work for like 10mins and I got nothing but cold air again. Well I just got to working on it today, I replaced my thermostat and a bypass hose(the one located next to the thermostat) that was blown, and by blown I mean it wasnothing but a big gash down the center of the hose, I replaced my fluids but I'm still blowing cold air. Also its not blowning as much air as it use to I'm getting roughly 30-40% of what it use to, though my you can hear the fan blowing just. I check the passanger side and there was no wet spots (first dodge I've own, and I was told that there would be wet spots on the floor of the passanger side if the heater core goes out). This honestly gots me my old man stumped. So if anybody can help it would be much apperciated

 

Check your heater hoses. They will be located on the right side of the engine bay in the back.

 

as Rt98 said i would check your heater hoses and as for the heater core...it will also go out if water freezes in it and it wont even blow...thats happened to us in the dead of winter...wasn't fun.. took it to the shop and the people said there was nothing but ice in the core...