Fluctuating neg. to ground on ignition coil

nm9stheham said
Since you are working on this, OP. Measure all the resistances of the spark plug wires. They should typically be in the range of 3000 to 6000 ohms and none should be over 10000 ohms. And check spark plugs for tight caps on the upper ends, and firm seating. How new are the plugs?

Measured all the spark plug wires today, got between 11000 and 12000 Ohm except for the short one between the ignition coil and the distributor cap that got around 5000 Ohm.

Spark plug wires are Accel radio suppression wires 8 mm.