References:
From back in time I spot this question, and have an answer.
> I picked up a pair of Heath/Zenith Dual Brite Motion sensing
> > porch lights. Mod# sl-4151-br1-b. The kind you can set to stay
> > on dim all night but turn on bright when motion is detected.
> >
> > I'm going to mount them either side of the 2 car garage door.
> > I want to wire them so that if either unit detects motion they > > both turn on.
> >
> > The directions call this a "dual master system" but don't tell > > you how to do it.
I had the same question and called Desa International, the makers of Heath/Zenith lights.
You need 3 conductor wire between the fixtures. Red is the control line - just connect it on all lamps. Wire all white to white, black to black and red to red. You can wire as many lamps as master of the others as the circuit will handle. On interconnected smoke alarms, there is a control wire. I bet motion sensor lamps at similarly.
Bill