when I read the post, the left cylinder header stayed cold, and the left coil was hot. When connected to 12v dc the whole time, that's when the points don't open, the coil will get hot, and die in the end. When connected to 12v, with 3.3 ohmns resistance gives 12/3.3 = 3.6 amps. That will generate heat.
So points aren't opening. Or the capacitor is faulty.
The schematics are very simple: one side of the coil is connected to the +12v of the battery. The other side of the coil is contacted to one side of the points, when point is closed, it is connected to ground( = -12v).
When point closed, there flows a current through the coil ( 3.6 amps), at the moment the point opens, there isn't current flow, but the capacitator that is connected over the point contacts, togehter with the coil inductance generate the spark.