no heat ? fan blowing cold air ?

 

You have the auto-hvac system or manual? Blend door is actually a fairly common problem with ford. If you have an auto unit, there is a self-diagnostic test you can run, just search the forums or google for it - it will spit out an error code if something isn't within parameters and help you pinpoint the issue. If your engine is getting up to temp, then blend door is your #1 culprit.

 

I would start by checking your coolant level as well. If it is low it could cause cold air to blow.

 

True also...^^^^

 

Everything said so far is right, but the second thing to do is check that both heater hoses are hot. The first being coolant level in the radiator.
If both hoses are hot, then it's blend door.