It has 3 wires because it is meant to be used with a receiver.
Depending on the controller's internal functions, simply wiring up black-negative & red-positive may be doable if you simply select the light function you want by first connecting it to a receiver before hard wiring it, or it may not, if the light control module resets to a default (usually "off") each time it is powered down. That white signal lead requires a PWM input, so it will need either a receiver signal or one from a servo tester.
If you simply want the lights to have on-off function with a normal SPST switch, you'll need to wire the LEDs directly to said switch. Be aware, however, that the controller may have an output amplification function as well, in which case directly wiring those LEDs to 5V or 6V power may result in them being less bright. Those incredibly bright LED flashlights aren't just battery power to LED; there is a tiny circuit board in there that amplifies the output to produce so much illumination.
I could be wrong here but here's what I think: The red is positive, the black is negative and the white is your ground. Kinda like a real car where the red is positive and the black is negative.
Don't mean to sound condescending here, but please stay away from automotive electrical systems. In a DC system, negative and ground are one and the same. And while red is
usually power and black is
usually ground, that is not always the case. As well, there will be both 12v and 5v circuits present in any modern automobile.
With 110V AC household wiring, black and white are both power; neutral/ground is green.
