When you say the brake switch seems to be working, are you sure the cruise
swtich in the brake swtich is working.  Just becuase the brake lights come
on does not mean the brake switch is ok.  There are several switches in one
brake switch and lots of times one will burn out and the others still work.
Check the on/off and resume switches also.  Make sure you have ground as
well as power.  I am not sure without looking at a diagram what wires do
what, but remember ground is just as important as power.