I really need to know which Ford you have, although the Explorer temp blend door is prone to breaking, and it will act just like that.
Fuses blow when there is a short circuit or an over current condition.
heater will not blow on a 1996 ford contour
if the heater does not blow out warm air change the setting.
No, not if it's on a heat setting. Most home thermostats have a "Fan" setting that will blow cold air if the attic is cold.
You may have a faulty switch that controls the speeds on the a/c blower fan.
There is no 1995 ford Expedition!
why my horn stop blowing
The same way you blow a normal bubble?
because it can
Wow, you got some talent! But no, that would not be seen as normal.
Some ford truck hvac systems will default to the defrost setting if the is a problem with the electrical or vaccum parts of the system. I encountered a ford truck that had a mouse living under the hood and chewed through the vacuum hoses and would only blow on defrost.Do a good visual check including electrical,such as fuses etc...