no spark

Copied from msd :

No 12v present at Coil +
1.One common question in regards to MSD Ignition controls is “Why isn’t 12V power on the orange (COIL +) wire?”
The main reason 12V won’t be present at coil + is because your MSD ignition is a Capacitive Discharge Ignition. Like all CD ignitions they use a large capacitor to discharge 420-480 Volts to coil + and coil – will normally be connected to ground. (That’s why you wont see +12V on coil +)

2.Most all stock ignitions are Inductive Ignitions, these will normally be connected to the + 12V ignition switch to coil + and coil – is connected to Points or the Factory Electronic Module. (That’s why you’ll see +12V on coil +)


http://www.msdignition.com/page.aspx?id=3206