I installed an FL-4 in an AirWire equipped engine. One function is for MARS light, one for number boards and the other 2 for the headlight, one for forward bright and the other for dim in reverse. The dime headlight works just fine. I did notice some slight flickering with the MARS light but not enough to be objectionable. There is no flickering with the dim headlight. I did not hook up the black/white wire at all.