I have an issue where I can not get my low beams to work.  When I turn the switch to the little dot the parking lights come on.  When I turn the switch to the big dot then nothing happens.  With the switch in this mode if I turn on the high beams they work. High beams off, no lights.

I do not know where/how to start troubleshooting.

The contacts inside the high/low switch at the base of the turn signal stalk get gummed up or corroded.  Some people take them apart and clean up the contacts, some just squirt a bunch of contact cleaner in and give it a good workout.  

The combination switch supplies power to both the high and low beams.  But the grounding in the switch at the signal stalk determines which beam lights.