My 1997 Nissan flasher unit is under the lower faschia panel on drivers side. There are 3 screws to remove and it is difficult to remove in any case. It is clipped to a panel bolted to the floor panel(but further up the panel between engine and feet) - it is easier to see with your head on the floor. There is a bigger unit next to it but it has three wires running into it and has a T shaped plug which is also difficult to remove
Kev, January 2010