Glowing Coil Terminal

I got a piggyback spade terminal, some wire, and a multimeter on my way home today. I hooked the choke up to the input side of the ballast. I checked the voltage between the positive battery terminal and the new connection. At a high idle it peaked right at .5 volts. I ran the car for about 10 minutes and there is no red glow on the coil terminal. Is there anything else I should check? Thanks everyone.