Second Brake Controller Question....
 

So I got my brake controller, and they also sold me another plug, that the guy said plugs into a panel under the drivers side dash.

I found the panel, but not sure which slot the electric brakes are, Plus, the red power wire needs to go to either slot a or slot d.

Also, there are just the wires under the drivers side dash, I would like to use the plug so I could take it out if I ever had to.

Has anyone used the "plug" or just the wires?

Thx,

JJ