Hello,
I removed the headlight bulbs to replace and I did not mark the wires. Not sure which wire connects where? There is a brown wire and a yellow and both are the same size. How do I determine which connector goes to which wire. Thanks! Driving dark in So Cal...

 

If both of those wires are going to same bulb, like H7 type, it does not matter otherwise they would install diferent plug to make them incomparable. Brown -, yellow +. On bulbs with two connectors, non of them is grounded. Check the other headlight and in the worst case you will blow a fuse.