Crank no start

Here we go again. 68 plymouth slant 6. Electronic ignition. Cranks but wont start. It will fire every once in a while. Pulled plug out. Has weak spark. Here are some numbers i have:
Battery 12.6 volts
-coil key on 1.3 volts
+coil key on 6.5 volts
Tested original brn/blue wire that went to ballast 8.6 volts crank/6.7 key on
Tested original blue wire that went to ballast 6.2 crank/11.0 key on
Here is a pic. Do i have it wired right? Original single blue wire has power with the key on.

7397CFFA-A8E8-4F7A-AA8E-25BCF745FADE.jpeg