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dclark1946's avatar
dclark1946
Explorer
Jun 14, 2016

Trailer brake wiring question( Mystery Now Solved)

Another question after crawling around under our new KZ Spree TT.

The wiring to the rear of the brake drums is only connected on the driver's side. The wires coming out of the back of the drums on the other side are taped off. Is the other side fed through the axle tube or what? The trailer brakes draw about 11A when supplied with 12V when using our electric trailer dolly.

I think I had measured brake current draw on each of the 4 wheels using a clamp on Ammeter on our 2007 Spree.

Mystery solved:

Thanks for your inputs. Based on those I was able to resolve this. My initial impression that the passenger side brake wires were not connected but just taped off was based on what I saw from the drivers side under the trailer where I could clearly see the wiring coming out from the plastic under belly liner and connecting to each of the brake drums. One of the wire pairs was laying across the top of the leaf spring which are mounted on top of the axle. I will need to reroute that pair. When I looked across to the other side to see how the wiring was routed I could see nothing but the wires coming out of the drums with tape on the ends.

This morning I decided to climb under the passenger side for a closer look. I did see a pair of black wires exiting the axle and connecting to the drum wires so what appeared to be taped off wires was really the connection to the wires coming out of the axle tube. Black wires, black brake drums and less then optimum lighting coupled with not knowing that manufacturers had started feeding the brake controller power down the axle tube led to my initial wrong conclusion. I am now a little wiser.
  • Thank goodness you found this and corrected it. It could have caused a genuine disaster.
  • myredracer wrote:
    dclark1946 wrote:
    Another question after crawling around under our new KZ Spree TT.


    We have a 2014 version of the same Spree model (except it has the different bathroom layout). I would suggest looking at the wiring in the A-frame area. Ours was poorly done. Plenty of corrosion and water trapped in upside down wire nuts inside the 4x4 metal box. The positive wire from the battery was completely loose in a ring terminal and fell right out when I touched it. You may fix the wiring at the brake drums, but you also need the connections from the trailer's wiring to the umbilical cord to work, especially for braking when you need it the most some day. I completely redid the connections and installed a watertight PVC junction box. I also redid ground lugs to the frame due to corrosion.



    The brakes in our TT are not grounded via the axle tube and have 2-wire cable spliced to the 2 brake wires. The wiring is awfully small gauge though and I plan to upgrade it when I eventually take down the underbelly sheeting.

    This our 2nd Spree TT and wiring does not appear to be their strong point. Have also found poor AC & DC terminations at the converter/panel (including completely loose wire at a breaker) and a couple of receptacles with reverse polarity.


    Thanks for the input. I will inspect the wiring and connections to make sure they are going to be reliable.

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