You have a short in the infite switches. Gotta find out which one, they run in series so one of them is bad. i would think that the larger one that turns on when you turn on the small one.
#54 on diagram (part#318120505)
you can order it from repairclinic.com if you wish. http://www.repairclinic.com/SmartSearch/SSPartDetail.aspx?PartID=501093&PPStack=1
It will not be super easy to find out which one it is, cause you will have to move the switches around to see if it does it to the other also. kinda like process of elimination. or you could just purchase one and then move it around till it fixes it. the large or the small that you mention of course is the one in question.