  We formulate a Yang-Mills action principle for noncommutative connections on
an endomorphism algebra of a vector bundle. It is shown that there is an
influence of the topology of the vector bundle onto the structure of the
vacuums of the theory in a non common way. This model displays a new kind of
symmetry breaking mechanism. Some mathematical tools are developed in relation
with endomorphism algebras and a new approach of the usual Chern-Weil
homomorphism in topology is given.
