Welcome to the wonderful world of Auto Repair. Technicians get the same kind of information many times. The sad part is it isn't always correct. Off the top of my head I don't know where your particular flasher is, but I would say if the info you have is correct, it is up under the dash and may require various components. To start with you should have a flsher on hand so you know what you are looking for. (webmaster-please don't edit my answer except for this sentence)
inside the gas tank
On a 1996 Mercury Cougar : In the fuse panel under the drivers side of the dash : ( there is a 20 amp fuse , the panel is marked " CIGARLTR" )
The evaporator emission system control valve on the 1996 Mercury Cougar is located on the left side of the car. It is in the passenger side headlight area.
Flashers are next to the fuses in the fuse box under the dash.
According to the 1996 Mercury Cougar Owner Guide : ( 18.0 US. gallons )
There isn't any fuse then is linked to the alternator on a 1996 Mercury cougar. The alternator has an internal regulator, but does not have a fuse.
The ( 1996 ) Mercury Cougar gas tank capacity is ( 18.0 U.S. gallons )
Look at the lower rear end of engine - follow cable from starter solenoid
I can't say for sure , but the ( 1996 ) Mercury Cougar is ( 18.0 US. gallons ) * also the 1991 Mercury Cougar is 19.0 US. gallons
The ( 1996 ) Mercury Cougar gas tank capacity is ( 18.0 U.S. gallons )
R134a
A ( 1996 ) Mercury Cougar gas tank capacity is ( 18.0 U.S. gallons )