The "Mystery Switch" is actually a switch that resets a "check engine" indicator on the dash. This was Suzuki's way to remind folks of regular service intervals before the advent of OBDI and OBDII service engine systems. When the "check engine" light lit up, you reach under the dash next to the steering column and throw the switch. The next - oft-ignored - step is to crack open the owner's manual and, by looking at the Odometer,
figure out what needs replacing. X-thousand miles later, the "check engine" light turns on and you throw the switch the other way.
"Thus the circle is completed..."
"This is CNN..."
"Luke, I am your Father..."
Sorry, I don't know what came over me just now...