Fluctuating neg. to ground on ignition coil

Did another measure of the primary side, now cold, measured 1.3 ohms.

But I don't know if its a thermal ballast resistor or not, think I have to remove it to be sure.

Should it be thermal or not?
(Another big question)

Very often the car idles very good after being shut down for 10-15 minutes, fooling me to think problem is solved, could that be the ballast resistor cooling down and lowering resistance?

Ballast Resistor.jpg