Tow ball electric problem

Discussion in 'Tech/Mech General' started by haganap, Sep 25, 2016.

  1. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,070
    Likes Received:
    13,680
    Location:
    Heavan
    When I plug a tail board in the rear lights come on...
    I've taken the black thing apart and all I can see is that there is not any obvious short unless there's something in the pins that I've not seen?

    any ideas
     
  2. Dave and Ginny

    Dave and Ginny Funster

    Joined:
    Jan 31, 2013
    Messages:
    1,334
    Likes Received:
    1,490
    Location:
    Nottingham
    Not sure what type of socket you have but assuming you have everything turned off in the van then to me it sounds as if you have a permanent live that maybe connected to the lighting board.

    Have a look at this and then you most likely need to check through each connection.

    http://www.watling-towbars.co.uk/wiring_guides_watling_towbars.html
     
  3. Geo

    Geo Trader - Funster

    Joined:
    Jul 29, 2007
    Messages:
    9,544
    Likes Received:
    5,596
    Location:
    Mansfield,Notts
    If its free standing trailer board
    Then it has to be a short in the plug of some desciption
    If you have used this board before without problems its going to be a wet spider stre hed between two pins or something as silly
    If its a new or new to you board suspect all and as advise check and confirm everything.
    If it's a toad your plugging in, good luck and let me know what it was:rolleyes:
    WD40 is your bext pal
     
  4. Glandwr

    Glandwr Funster

    Joined:
    Jul 10, 2014
    Messages:
    618
    Likes Received:
    1,693
    Location:
    the Berwyn Mountains
    By the "black thing" do you mean the one, under or in the van, full of relays that isolate the board electrics? There is a permanent live feed in some of theses that could have a short.

    Dick
     
  5. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,070
    Likes Received:
    13,680
    Location:
    Heavan
    Well this is where I am at now...thanks for all your help BTW...

    I took off the socket got a new one and re wired it as per last socket to make sure it was the same and no joy same thing as before...

    Therefore I rewired again but this time a bit further back on the cable..there was a bit of a frazzle and I was convinced I had blown a fuse. Despite searching I couldn't find anything blown.. I put it all back together and have cured one problem and created another.
    The lights are no longer on but I have no indicators the stop lights work aso do the tail lights. .would the indicators be on a separate fuse somewhere. ? I have checked the connector in the plug and it all seems OK. .
     
  6. Glandwr

    Glandwr Funster

    Joined:
    Jul 10, 2014
    Messages:
    618
    Likes Received:
    1,693
    Location:
    the Berwyn Mountains
    How old is the van? When was the towbar fitted? Do the van electrics work correctly when the board is not connected? Do they work correctly when the board is connected? Frazzled? were you rewiring while connected?

    If it was a recent fitting there would be the relay box I mentioned earlier, either beneath or inside the van. Can you trace the other end of the cable back?

    Dick
     
  7. TheBig1

    TheBig1 Funster Life Member

    Joined:
    Nov 27, 2011
    Messages:
    7,224
    Likes Received:
    9,612
    Location:
    Dorset
    screwed up bypass relay by the sound of it. have seen some truly shocking installs where the relay is under the van with poor insulation so it corrodes and fails as described
     
  8. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,070
    Likes Received:
    13,680
    Location:
    Heavan
    Yes Dick I've seen the box under the van. Covered in gaffer tape.

    2009 Mercedes Rapido. ..everything works fine on the van
     
  9. TheBig1

    TheBig1 Funster Life Member

    Joined:
    Nov 27, 2011
    Messages:
    7,224
    Likes Received:
    9,612
    Location:
    Dorset
    gaffa tape? theres the problem. knackered bypass relay. replace and insulate properly
     
  10. Glandwr

    Glandwr Funster

    Joined:
    Jul 10, 2014
    Messages:
    618
    Likes Received:
    1,693
    Location:
    the Berwyn Mountains
    Agree with the bigone a bypass relay failure. Disconnect it open it (just a series of small box relays) and look for any water damage. If it can be cleaned up all well and good. If not google any part number you find along with the words "bypass relay" and you may find a straight like for like replacement for less than 20-30 quid.

    Essentially what it does is work the board in tandem with the vehicle electrics but at the same time isolating the two circuits in case of damage to sophisticated electronic elements in the vehicle circuits. The box itself is simple technology.
     
  11. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,070
    Likes Received:
    13,680
    Location:
    Heavan
    Cheers guys. .van going in for some other work soon.will get them to do it.
     
Loading...

Share This Page