The malfunction indicator light (MIL) illuminates to indicate to you that the computer has detected a fault in the engine/transmission/emission control systems. A scanner is required to access the data and diagnostic codes stored in the computer. It's not possible for me to know whether your husband can repair the problem without knowing his experience, tool availability, and exactly what's wrong. Without a scanner, there isn't much hope and a manual may be necessary for information about the systems and specs involved. You may need to consult an expert. if your husband has a scanner and wants to take this on, there are online manuals available as follows:
Here are two sources for you:
For AllData:
http://bit.ly/AllData_Repair_Manuals_Online
Here's the one for Mitchell as well:
http://bit.ly/mitchell_repair_manuals_online
If you want to find a Ford specialist, here's a directory link for you:
https://repairpal.com/directory?address=87024&car_brand_n...
PS: I don't think you should have had to pay for labor for a warranteeable problem. That's what warrantee is for.. I'd have found the Ford representative in your area to ask for compensation if the dealership didn't listen to reason. I hope you avoid that dealer in the future unless there was some reason I don't know for you owing money for a warrantee repair, even for diagnostics..