I don't have an immediate answer for you..., but if you contact Jayco Customer Support (have VIN handy) they may send you the wiring schematic for your Octane.
Check out page 10 in this Dexter document (there are additional electrical references as well): http://www.united-trailers.com/Uploa...s/Manual_6.pdf
From Dexter FAQ's: "BRAKES - Do Dexter brake magnet wires have polarity?
The wires on a Dexter magnet do not have polarity. It works like a common resistor. One wire will connect to power and the other to a ground. It is Dexter's recommendation that a common ground be run from the trailer plug to the brake magnets. Do not ground each brake individually to the trailer frame or structure. Also note that the brakes should be wired in parallel, not in series." http://www.dexteraxle.com/faq_s
Also, according to the following video (@ 5:40) the brake magnet has two wires coming from it, and apparently it doesn't matter which wire as long as one goes to a positive connection and the other to a ground connection.
Hope this helps.