91 ranger problem

I have a problem with heat coming through my vents. The heat is not on, but it seems as if the heat from my engine is coming through the vents. Im wondering if this is just a problem everyone has had with the 91 ranger or I have a problem and dont know what it is. I would really appreciate if someone can give me some feedback on this one. And also, is there a really good website that anyone knows of that has anything and everything you can buy for a 91 ranger. Parts , interior and exterior and thing like that. Trying to fix it up but really battling this heat through the vents thing right now. Thanks so much to anyone that can help.

if you have the temp setting to heat a small amount of heat will come out; even if the heater is turned off. turn the temp setting to cold and it will close the vent