MSD install help needed

The small red is a "power enabling" wire, think of it as a relay trigger. Make CERTAIN it has power

For "simplified" testing, you can just jumper the small red right to the battery

MAKE CERTAIN and I do mean absolutely certain that the "big red" is very well hooked to the battery and not some slipshod deal, and that the "big black" has a substantial ground

You did not mark the ground, coil neg, and coil + colors, is it possible you have them screwed up?

DO YOU HAVE a tach hooked up? If so UNHOOK the tach

Make certain the WHITE from the MSD is taped off safely.

READ the MSD destructions, there are test procedures. Also, was this running OK when you put the MSD on there?

(One test is to repeatedly ground the white wire which is for points. This should produce nice hot sparks.)

It's always possible that you have a factory defective box.

Is it possible the coil is bad?

Coil high tension wire?

Dirty/ wet / cracked distributor cap or rotor?

Last is it POSSIBLE that you have stumbled onto an MSD pirate/ chineseo fake?