Ballast Resistors

Racing got rained out so I got my machine mocked up last night with a chrome box and the dual ballast resistor in question from the video. I will only be testing the coil side of the resistor as the chrome box is a 4 pin box. Waiting on an amp clamp that I ordered that won't be here until next week. That should make it easier to get current readings at different places quickly.

Thinking in my head how to do the test. I think I will need to measue current in two places. (1) At the power wire feeding the ballast. I'm going to have to seperate the module power wire from the ballast terminal to isolate the resistor feed circuit. (2) at the feed wire to the coil after the ballast. Then subtract the coil feed current from the ballast feed current to calculate the restance at the ballast. While simultaneously measuring the temperature of the ballast. Does this sound right?

Measuring the temperature of the ballast might be hard. I think the temperature will be very localized within the resistor at the windings. I think I will have to test at two rpms one low and one high. It will have to remain at a steady rpm long enough to heat soak the entire resistor. Then try to measure with an infrared tenp gun. Or I think a better way to measure temperature might be to measure at the terminal with a temp probe and some heat sink paste. I think I will just have to play around with it and see what gives consistent temp measurments.

I say "I think" a lot because I don't know. If someone sees a flaw in my thoughts or has an idea how to do it better feel free to share or better yet join in the testing and add your results. Keep in mind I am limited on resources, especially time and tallant.