What activates them? Did you just tie them into the existing flasher/turn on the sprayer?

If so, I assume these flash also when not turning?

I heard a safety bulletin on the radio a couple yrs ago by IL St Police. They were addressing farmers. He said one problem is that cars behind you have been staring at your flashers for miles in some instances and they don't notice when you go to the turn signal mode. Not much changed....one continues to flash while the other stay steady. Drivers just don't comprehend the change.

Perhaps your lower placed arrows will help solve the problem as long as you don't drive for miles with the turn signal on, though most fairly new units have some type of warning after extended driving with turn signal on, unlike semi trucks.