I bought the new LED rail light because someone smashed out my stock tail lights. So instead of just buying the stock looking tail lights I bought these. And I rarely use the cruise control so no haven't checked it.I don’t understand the whole resistor workaround. Resistors convert electrical energy into thermal energy - heat. I’ve heard the resistors get too hot to touch, but I don’t know this for sure. But that’s a lot of energy. So your power draw and current probably actually goes up with the resistor inline in series with the LED fixture. LED on the stop lights and flashers in an old GM SUV is a solution looking for a problem that causes another problem, is what I think. Why not just replace the fixture with new crystal fixture (or polish the old one) and use LEDs for the backup lights and 3157 incandescent clear and amber for the stop light and flashing turn signal lights?
By the way, have you checked your Cruise Control?