Check owner's manual. If you don't have one copy and paste link below; www.fleet.ford.com/maintenance/owners_manuals
fan relay on 97 mustang with 3.8
in france
The fan relay is most likely stuck closed. Remove the relay to see if the fan stops running, if the fan stops, replace the relay.
as long as it is the same as a 98 it is a fuze not a relay
underneath battery
Possibly an internal short on the fan itself, try replacing the fan.
They should be coded. On mine the relay is the green one under the hood.
one of the fan belts is broken.
Check the rear of the radiator approx. 1/3 from the top
change the coolant fan relay
It should be in the fuse panel under the hood.
A relay has gone bad.