lost juice to the starter!

[65BD427r]

I have a Backdraft cobra, less than a 1000 miles on it! Vehicle had been running great, parked it came back out after it had cooled down and tried to restart it and non thing happens, like i had turned off the red switch! I checked to see if i was getting any fire to the starter (main red wire coming from the shut off switch) and wasn't getting any fire! I pulled the cover off the cut off switch and it showed i was getting fire to the wire coming from the battery but non thing going out to the starter! I noticed the nut was a little loose, tightened it and rechecked it and it fired right up! Turned it back off, put everything back together and decided to check it again, click it went dead again! The only thing i can figure is that i've a bad connection or bad shut off switch! I plan to start there tomorrow and first off will probably by pass the switch and wire it directly to my positive side of the battery to see if that works, if so i assume i have a bad switch! Any other suggestions, would be appreciated, thanks. Also i had noticed my starter has been dragging a little when i start it, will probably have it checked out also, possibly needs rebuilt or replaced! The engine in the car is a Roush 427R- 550hp. No other problems, love the car, thanks