Wiring Woes

Colin Dav
Colin Dav Forum Participant Posts: 51
edited May 2022 in Caravans #1

Last time I took the van out (2010 Rambler 19/4 SE(based on an Elldis Avante 540)) I managed o let the electric tow cable drag on the floor causing wires to break (or wear through). So i managed to effect a temporary repair to get us home. 

I have decided to replace the cable back to the van and decided to mount a couple of Wago terminal boxes close to the power supply under the seat of van, into which I have terminated the new cable. I have cut back the old cable to about 2 foot and begun to terminate this into the terminal boxes, however when stripping back the last cable on Pin 13 (earth return for Pin 9 the permanent 12v live), I have noticed that all the strands are blackened. This supposes me as all the other cables are perfect. I don't think it has been caused by water ingresses this is the only cable that has the problem and it seems to be all along the cable. I suspect over heating but the supply wire was perfectly ok. Both wires are 2.5mm 

 

Any Electrical Engineers have any theories? 

I am planning to cut and clean this wire close to the power supply plug which it feeds into and run another short piece of earth wire along side, terminating all three into a wagon to maintain continuity.

Comments

  • Navigateur
    Navigateur Club Member Posts: 3,880 ✭✭✭✭✭
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    edited May 2022 #2

    The black appearance is oxidation of the copper from moisture or overload, probably the later as other circuits use this as a common earth.  It should really be cut back to clean copper but that could be the whole remaining length. If it is not replaced, when it fails a number of circuits will stop so will be a major problem if on the road at the time.

    Quick fix is to abandon that core and run a thicker additional wire under your caravan to your new junction boxes.

  • RedKite
    RedKite Club Member Posts: 1,717 ✭✭
    500 Likes 1000 Comments Name Dropper Photogenic
    edited May 2022 #3

    If the wire for T13 (white/red) is discoloured, but not the wire for T9 (orange) then there is a possibility of 'economical' wiring of the caravan car, and T13 is doing more than its fair share. T13 and T9 should only be the permanent 12 supply to the caravan and would (should) do nothing while you are towing. T11 (white/black) with T10 should be working to supply your fridge and battery charging, they will work while you are towing, and do nothing on site. If anything is going to overload, it would be the T11 and T10 pair.

    Also just do a quick check on the car, T3 (white), T11 and T13 should all be wired independently back to a good chassis point in the car.

    There is a chance that T13 is doing the work of T3 and T11, which will 'work' (for some alternative definition of work).

    Also, check the replacement cable that you fit to the 13 pin, I have seen cables made up with all the came cable rating, (popular on an online site that has a relationship with rain forests). Proper cable will have different thicknesses for the different current loading.

     

  • PeteCI
    PeteCI Forum Participant Posts: 66
    edited May 2022 #4

    The permanent 12v supply should provide the battery charging current while towing. It will normally be connected in the caravan pdu by a relay operated by the fridge supply when car engine is running.

    If the fridge and battery are connected to the same supply cable (t10) it may flatten your caravan battery while you travel. But your beer might be nice and cool 😎

  • Colin Dav
    Colin Dav Forum Participant Posts: 51
    edited May 2022 #5

    Thanks Guy's

    I've changed the whole cable length, apart from the last couple of foot in the van and the new cable has 8x1.5mm cores and 5x2.5mm cores and i've made sure the right ones go to the correct pins. I will check the car socket to ensure that everything is good there. 

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