A blower motor can quit suddenly. What I would do is access the blower motor and disconnect the plug. Check the plug for burning as that is a common problem and Ford I believe even offers a pigtail repair kit for this problem although it can be worked around without going through Ford.
A burned plug is caused by long term operation of a blower motor that is dragging.
Just took a quick look and even AutoZone shows a replacement plug if needed.
The EATC models can suffer the same problem although a blower speed controller module comes into play there. Sometimes the modules can overheat and melt a bit for the same reason; a dragging blower.
Just a note about blowers. A few years back my wife said the fan had quit in our Lincoln but came back on after a few minutes. When I checked it the fan was blowing fine and making no noise.
I dropped the knee panel and put an ammeter into the blower motor circuit.
On HIGH speed that blower was pulling 27 amps and needed to be replaced.
Wonder why the wire plugs burn… 