Power to breakaway brakes

ScottG

The recent thread about battery cutoffs appears to have ended in some drama. While I have no desire to resurrect the "positive vs. negative" argument, there were some repeated statements made regarding the safe operation of the the emergency braking system that are not consistent with the anatomy of my 2015 M@x-S.

There is only one wire from each battery terminal (ignoring the Zamp leads, which go nowhere). Those wires run to a junction box under the trailer where they split into two branches serving the converter and the emergency breakaway switch. Therefore, if you disconnect the battery in any way prior to that junction box, your breakaway brakes will not operate in the event of trailer separation.

So, if you are concerned that your breakaway brakes work as intended, don't drive around with your battery disconnected.

But... if you must drive around with your battery disconnected, install your cutoff inside the trailer between the junction box and the converter. This will maintain 12V to the breakaway switch at all times.

Forgive me if I'm stating the obvious. There are people who come here with little technical background looking for the "right answer" who may not be able evaluate the merits of various responses. That's fine if we are debating awnings vs. tents. It's not so good if we are talking about the operation of a critical vehicle safety system.

Don't take my word for it (or anybody else's). Get out there, follow the wires yourself, and start learning about this neat little camper! Here's a photo of the junction box: