74 Tailight Problems

So I unplugged the rear wireing harness that leads to all the lights in the rear and the fuse still popped so that leads me to the instument cluser. So i pulled the gage cluster out and now i can't get the car to start at all. The car will crank but will not fire. It also has an MSD ignition system in it any ideas and i still cant get any the tailights or any lights to work now