  Wiring diagrams usually serve as a tool in the study of arrangements of lines
and pseudolines. In this paper we go in the opposite direction, using known
properties of line arrangements to motivate certain equivalence relations and
actions on sets of wiring diagrams, which preserve the incidence lattice and
the fundamental groups of the affine and projective complements of the
diagrams. These actions are used in [GTV] to classify real arrangements of up
to 8 lines and show that in this case, the incidence lattice determines both
the affine and the projective fundamental groups.
