I have six 4" recessed lights in my dining room used 12/2,
I wired it to og wire at bottom corner light running counter clock wise to the next lights, until Im back on the same side just next to the light started on, everything looked OK so I went to switch back the breaker and came back the lights were on, but switch was OFF. So when I switched it on the fuse jumped. Im at lost here if anyone can help in the next 24 hrs I greatly appreciated. The lights are 50watts, the original wire is old and didn't have ground.

Need more info. Where does power come from? Color of wires to the first light? Describe all wiring involved.

Chuck

Two concerns - HEAT and supply.

With recessed lights you have to choose the type of light correctly. Some lights are "IC" (in contact with insulation). These can be covered with insulation and nothing will happen. If the lights you chose were non-IC lights, then no insulation can be within 3" all around the light. If a non IC light is covered with insulation, it will cut off when it gets hot and come back on when it cools.

I need to know where the supply for the string of lights is. Is it brought to the switch and then routed to the lights or is it routed to the lights and then brought to the switch to control the lights.

This is critical, if you have a miss-wired "switch loop" then you have Neutral and Hot at the switch instead of just the Hot. Normal run of the mill switches only interrupt the Hot conductor.