Tow bar electrics

GuyAndFran
GuyAndFran Forum Participant Posts: 9
edited December 2019 in Caravans #1

Good morning all. Hope you all had a happy Christmas.

Advice required please. When connected my van to my car with the power cables. Should this charge my caravan battery.

Regards

Guy 

Comments

  • Metheven
    Metheven Club Member Posts: 3,987 ✭✭✭
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    edited December 2019 #2

    Bit more info needed Guy,

    On the car is it one 7 pin (12N) or two sockets (12N and 12S), 12S used for fridge and charging or have you the one 13 pin that does it all (if connected fully)?

    Also is your cars loom wired to full spec, ie to charge the leisure battery and provide 12v for the fridge. Have you the additional wires on the correct pins?

    What plug(s) have you on the caravan?

  • Cornersteady
    Cornersteady Club Member Posts: 14,428 ✭✭✭
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    edited December 2019 #3

    Well it should if fully wired up correctly as Metheven says. I have spoken to a someone once on site, asking about their tow car and they said they let the dealer who fit the electrics and the charge/fridge (and ATC I believe) were not wired up.

    You can buy a cheap test device from amazon that will check everything out, each light and things like fridge/charging/ I bought mine for about £10 I recall,

     It was something like this one here but there are some more expensive ones as well

  • commeyras
    commeyras Club Member Posts: 1,853 ✭✭✭
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    edited December 2019 #4

    As has been said the answer is 'yes' if correctly wired up; only when the engine is running though at, at above tick over.  Put a meter over the caravan battery terminals, with engine running at reasonable revs, to check.

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited December 2019 #5

     .... and then there are 'smart alternators' which can cause charging/fridge problems .... 😉

  • KjellNN
    KjellNN Club Member Posts: 8,670 ✭✭✭
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    edited December 2019 #6

    It can be a minefield these days!

  • davetommo
    davetommo Forum Participant Posts: 1,430
    edited December 2019 #7

    Turning off the auto stop start cures the problem on my discovery sport

  • JVB66
    JVB66 Forum Participant Posts: 22,892
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    edited December 2019 #8

    The towbar company that have done our last few tow vehicles recognise the "smart alternator"problem and now fit some sort of "resistor? "In the wiring to the 13pin socket to overcome the problem

  • KjellNN
    KjellNN Club Member Posts: 8,670 ✭✭✭
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    edited December 2019 #9

    We turn off the auto stop as recommended by VW, but were  still not certain that the van battery and fridge were being powered.  These new cars are far too smart!

     

    To be certain, as having the van battery charged was essential for us for using the mover, we have fitted a "battery to battery"charger and now have no problems

  • lornalou1
    lornalou1 Forum Participant Posts: 2,169
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    edited December 2019 #10

     dependig on what caravan you have, the control panel should tell you what is charging the battery, ie mains, solar or vehicle (when engine running)

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited December 2019 #11

    won't  the caravan's habitation relay knock all that off? I honestly don't know with mine ... I've just looked through the window in the door to see my fridge is ON when I've hitched up & the engine is running.

  • KjellNN
    KjellNN Club Member Posts: 8,670 ✭✭✭
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    edited December 2019 #12

    We had no problem with this on our 2007 Volvo, but our 2016 VW Touareg is a totally different proposition.

  • Cornersteady
    Cornersteady Club Member Posts: 14,428 ✭✭✭
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    edited December 2019 #13

    yes indeed, when I was testing the new car with the engine running, in the 'picture/diagram' of car and caravan, the car's 'picture'had an illuminated flash symbol in it. It isn't there when switched off.

  • KjellNN
    KjellNN Club Member Posts: 8,670 ✭✭✭
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    edited December 2019 #14

    When we first tried our 2008 van (which worked as it should with our 2007 Volvo) with our 2016 VW, nothing worked as expected when connected to the car, it even prevented us getting power from the van battery when stopping en route for lunch.  We had to unplug the van from the car to be able to get power.

    Since fitting the battery to battery system in early 2018 we have had no further problems.

  • lornalou1
    lornalou1 Forum Participant Posts: 2,169
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    edited December 2019 #15

    Don't know, when I connect car the panel says "vehicle is charging battery" and then I set fridge to battery and of I go. Don't try anything else as not required when moving apart from the caravan rear lights etc.

  • Amesford
    Amesford Club Member Posts: 685 ✭✭✭
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    edited December 2019 #16

    Yes it Should charge the battery and run the fridge but only when the car engine is running, it should automaticlly disconnect when the engine is turned off otherwise it would drain your car battery but we do prefer to plug our van into the mains prior to going away to fully charge the battery and cool the fridge thus taking some some work off the poor car engine

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
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    edited December 2019 #17

    My caravan auto selects depending on what flavour of electric/power is available. 

    This panel you describe  .... Is that car/Jeep or caravan?

  • KjellNN
    KjellNN Club Member Posts: 8,670 ✭✭✭
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    edited December 2019 #18

    https://www.12voltplanet.co.uk/sterling-pro-batt-ultra-battery-to-battery-charger-12v12v-30a.html#product_tabs-0

    For anyone with one of those "smart alternators", this is similar to the one we fitted.  Good explanation of how it works too.

  • lornalou1
    lornalou1 Forum Participant Posts: 2,169
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    edited December 2019 #19

    Caravan. Swift Command 2019.

  • KeithL
    KeithL Forum Participant Posts: 114
    edited February 2020 #20

    On my VW the stop/start is automatically turned off when a trailer is connected. Sounds like a bit of coding of the towbar module might have been missed by your fitter if you have to turn yours off manually

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