all the outputs are labeled positive and arc to each other(very confusing)
The push button lighters have a positive lead and use the grill body as the ground.
its a battery powered igniter and has 4 + leads(and a ground)but the 1st positive arcs to the 2nd, 3rd, and 4th, the 2nd also arcs to the 3rd and 4th, and the 3rd also arcs to the 4th(they all arc to each other)AND NONE OF THEM ARC TO THE GROUND!!!!!
The the circuit is creating a high voltage alternating current so no ground is needed. You have an active wire and a neutral wire. When 1 is activated 2 acts as the neutral and so on. If it's working then don't worry about it.