Insensitive traffic detection loops are a common problem. The 2009 and
2010 Indiana Bicycle Safety legislation proposal had a specific
provision that allowed bicyclists to treat these lights as a 'flashing
red' and proceed through the intersection. Unfortunately, the bills
failed to pass.
In spite of that, these detection loops are supposed to work for all
vehicles, including bicycles. If the loop doesn't work, it is
defective, and there is no law that says vehicle operators must abide
by defective traffic control devices. So, if the way is clear, you can
legally cross the intersection if it is safe to do so. (Disclaimer: in
my opinion).
That only partially solves your problem: I'm sure you would prefer
that the loop be repaired, and brought up to standards. The person to
contact is the Mishawaka City Engineer. You can report the problem at
http://mishawaka.in.gov/trafficsignalissues, or you can contact the
engineering department directly: see
http://mishawaka.in.gov/engineering
for phone and e-mail contact information. Don't hold your breath.