1966 Plymouth Barracuda Help!

Also i Have 11-12v going to the coil but when i read the end of the Coil wire going to the distributor it gives me 4-5v. Also tried getting Spark from using a plug wire but still nothing. I have the wire running from the distributor going to the negative. and the wire coming out of the firewall to the positive. I also ran a wire from the positive to the battery but that didnt seem to help.