Volkswagen: ignition switch hookup, street legal dune buggy, starter solenoid

Question
Hello Rick,
I have a street legal dune buggy here in Houston.  We recently changed out the ignition switch, but we went from a 4 post to a heavier duty 3 post.  After hooking up all the wires, the motor won't stop after turning the key to off and pulling the key out.  I have to pull the alternator wire off each time to stop the engine.  Help!  Is there a wire I can run from the switch back to the alternator to make it work properly?
Thanks a lot,
David

Answer
David,
 Any ignition switch should have 3 positions: OFF, ON, START.
As far as contacts with a three post, these should be COMMON, ON, and START.  Assuming this is what you have, you need to determine COMMON with a multimeter, unless it is already clearly marked.  Connect this contact directly to battery power.  The ON contact should be connected to the COIL positive terminal; this should properly feed all ignition circuits.  The START should be connected to the starter solenoid.  This should fix the problem.  Otherwise, there is some other source positive voltage connected to the ignition circuit incorrectly and needs to be found and removed.  
-Rick