the wire from ignition switch(ignition-on)to +coil on my vw based car with the vw factory harness ,shorted at the coil end from one wire rubbing on the engine tin. this wire is not fused and melted all the way to the ign switch. the result was not fun to fix. however , the ignnition switch burned up stopping a complete meltdown. i have since read that this is a common problem. so if you have my setup put a fuse ( i used a 20 amp)close to the coil connection . on my car the wire also powers the backup lights and the carb idle cutoff and choke.