a switchor the the relay to the fan is blown open. take a tester start at the blower and test back wards. If all fails put a kill switch on the battery.as a quick fix. But each time you restart your coputer has to reset it might run rough for 10 miles/min. and u have to fix your clock & raido stations. If you mean the heater fan i think its a purple wire to the fan is hot.
battery
under right side dash, near blower fan. has two screws & connector.
Are there issues with the electronics?
You might try adding water to the engine. That is what was wrong with mine.
I tested mine by putting wires with alligator clips on the blower's terminals and touched the other ends to my battery.
find blower motor check for voltage on one of the three pins at blower motor, if so check for good grd. most likely ur blower motor is fualty.
Did you by any chance make a spark removing that battery? If you did or didnt I suggest you check the fuse
Possible bad alternator.
Motorcraft BXT - 65 - 650 according to the 2000 Ford Expedition owners manual ( Ford also has cheaper batteries available )
The relay is right behind the battery. The lead got bumped off when removing the battery to get access to the blower motor.
iT CAN BE EITHER FUEL OR FIRE. taKE IT TO A GARAGE.
Check your owners manual. If you don't have one copy & paste this link. http://www.genuineservice.com/genuineservice/en/gloveboxresults