Msd run-on!Has anybody experienced this?

I have installed a MSD 6AL box and ss coil in my 66 Dart with factory mopar elec. dist.I have the car running,but when I go to turn it off with the key,it stays running?In the instructions,they call this run-on.It says to put a jumper wire on the dual ballist on one side and little red wire on the top and run a ground to the bottom on the other side.Has anyone tried this with good results?Thanks,any help would be great!

P.S 360 LA engine