Try the plug wires first. I'll bet that's it.
You can see if the alt wire is doing anything by pulling it loose and starting the car, then look for changes in behavior.
Also, try running a continous independent ground wire from the motor to the control box. Just a temporary one will tell you what you need to know.
my signature lines...not really directed at anyone in particular..
BE different....ACT normal.
No one is completely useless..They can always be used as a bad example