MSD & Alternator Light - Diode?

[vntgspd]

Okay, after searching the many threads for hours, I have gleaned some great info but am also a bit confused - so please don't flame me or tell me to search!

I finally got my MSD, Blaster SS coil, and tach adapter installed last night. I have spark and the car runs. When I turn the ignition off, the alternator light illuminates.

Here's my setup:
MSD (+)Red to 12v source at rear of engine compartment electrical panel
MSD Ground to chassis ground on inner fender (most engine electrical seems to be grounded to this lug)

MSD switched 12v(red) connected to red wire after fuse block that was powering Perma-Tune (verified switched 12v), red tach adapter wire, & red wire from pertronix
MSD white trigger wire connected to black/purple tach wire, black pertronix wire, & white wire from tach adapter
MSD orange and black coil wires are attached to coil correctly


Most of the technical issues seem to relate to engine run-on which I do not have. Everything appears to work normally, including the tach. The only issue I see is that the alternator light illuminates when the key is switched off.

It sounds like power is bleeding through the MSD somehow and I think I need a diode to "block" the voltage. Or do I need a ballast resistor???

Am I on the right track here?

Where do I put the diode in this case?

Which direction should it point to (i.e. block voltage from where)?

Thanks!