Volvo XC60 towing electrics issues

jptmail
jptmail Forum Participant Posts: 5
edited August 2020 in Towcars & Towing #1

Hi all. Recently had a towbar and dedicated 13pin electrics fitted to our car. When the fitter tested it all was fine. However, in real life, the brake lights & indicators are fine, fridge supply fine, but... reverse lights only work intermittently and only if shifting quickly from neutral into reverse (it’s automatic gearbox) and not every time. Running lights mostly work but sometimes don’t come on at all and sometimes just ones side. Fog lights only come on if switched on, off and then on again.I’m stumped to say the least. Caravan side of things all ok, clean connectors etc, just serviced. Reverse lights on car fine every time. Any thoughts... TIA

Comments

  • lornalou1
    lornalou1 Forum Participant Posts: 2,169
    1000 Comments
    edited August 2020 #2

    This must be one of the most asked questions about Volvo electrics. I know this sites search engine is not to good but have you done a search just to see if answers are out there. Not much help I know. 

  • jptmail
    jptmail Forum Participant Posts: 5
    edited August 2020 #3

    Thanks. Yes, done a search but to no avail. I’ll try again though

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
    1000 Comments
    edited August 2020 #4

    the usual question asked is why the fridge & battery charging don't work, your problem seems to be more hit & miss which would suggest to me either iffy connections in the plug &/or socket of the car or caravan or maybe where the 12v supplies in the car are taken from. Have you a friend or  neighbour with a known to work 13 pin socket on their car that you could try on your caravan to narrow the fault to either car or caravan?

  • jptmail
    jptmail Forum Participant Posts: 5
    edited August 2020 #5

    Thanks, I have the caravan has just been serviced and electrics we’re fine, so pretty sure it’s car side. Modern electrics and older caravan. The caravan used to have the twin electrics but was upgraded to 13 pin socket and worked fine with last 2 towcars 🤷🏻‍♂️

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
    1000 Comments
    edited August 2020 #6

    That does suggest it's your car then 🤔 I can only suggest you take it back to the installer

  • asda160
    asda160 Forum Participant Posts: 87
    edited August 2020 #7

    As a fellow Volvo owner who frequents the Volvo UK owners forum I have not seen such an issue raised as suggested by "lornalou1" nor does a search of the Volvo forum raise such a repeated issue.

    You say the wiring is dedicated. Genuine Volvo or aftermarket ?

    If it's the former, did the fitter get the dealer to upgrade the software so the trailer module communicates with the car?

    A simple test with a multimeter into pin 8 of the car socket (pink wire)and to earth pin 3 (white wire) will clarify if the reverse light function is live all the time when reverse is selected or if it is sporadic, ie bad connection between car and wiring or fault on the towing module.

    If you get the latter then it would appear you've paid good money for a product that doesn't work as it should, so go back and politely exercise your consumer rights.

    If it shows as working via the multimeter then is time to check the caravan socket. Just because it was serviced don't assume there isn't an issue there. A loose or corroded connection can happen at any point.

    Car electrickery can be a fickle beast and more so with a complicated car such as a Volvo which has circa 10 computers to monitor individual components.

     

  • jptmail
    jptmail Forum Participant Posts: 5
    edited August 2020 #8

    Today I discovered that having 2 reversing lights caused the issue. Took one out and everything is perfect. Now got to work out how to get both working, possibly lower wattage bulbs, or LED. No, the software hasn’t been updated by Volvo but seems to be ok. That’ll be another discussion!...

  • EmilysDad
    EmilysDad Forum Participant Posts: 8,973
    1000 Comments
    edited August 2020 #9

    Try two led bulbs then & see how you get on.

     A while back on CT someone had a problem with their caravan and the 4 stop/brake lights ... all was resolved by replacing 2 of them with led

  • asda160
    asda160 Forum Participant Posts: 87
    edited August 2020 #10

    Ah, so it is a current draw thing. 

    Thanks for updating, so many don't. Will be useful to others in the future. 

    I've heard of this for fog lights on a caravan.

    I suspect the car lighting control module(LCM) expects to detect no more than 42w current draw of the cars own bulbs and when it detects over this with another 42w of caravan bulb it thinks there's a fault and shuts down. 

    If you have access to a code reader or better still Vida, Volvo diagnostic system you may have fault codes logged in the LCM

    This would suggest that the towbar wiring fitted whilst vehicle specific is not Volvo OE, hence why there was no trip to dealer for software. 

    Sounds like you may need canbus compatible led bulbs to lower the amp draw.

    A good place to ask for help is here Volvo forum

     

  • Phishing
    Phishing Forum Participant Posts: 597
    500 Comments
    edited August 2020 #11

    Try non canbus compatible LEDs (although why they are called this is beyond me). The ones called canbus compatible have built in resistance to the equivalent of a filament lamp so will have no difference to fitting a standard bulb. The plain LEDs will have minimal current draw. Given the sensitivity of the system you may need one of each to get the correct current draw.

  • asda160
    asda160 Forum Participant Posts: 87
    edited August 2020 #12

    Yeah I got that wrong. Non canbus is the correct way

    .... and they call this canbus system progress, single wires for multiple functions and computers that need exact voltage/amps or they spit their dummies out. 

    One thing of note is that the Volvo OE wiring suffers none of this on my 2015 XC70. 

    My last van was an Elddis with Std lamps and two reversing lights and no issues and my current van, an Adria, has led lamps and there are no issues. 

     

  • jptmail
    jptmail Forum Participant Posts: 5
    edited August 2020 #13

    I’ve ordered these LED replacements and will report back to how they do! 

     

     ARH Auto Accessories P21W Cold White 50 SMD COB Reverse Light Bulbs - Twin Bulb Pack – Straight Replacement For Any P21W / Reverse Bulbs - FREE 12 Month Warranty https://www.amazon.co.uk/dp/B01N4WV4B0/ref=cm_sw_r_cp_api_i_ISqlFb9DE1WVQ

     

     

  • ydna
    ydna Forum Participant Posts: 20
    edited September 2020 #14

    I have a similar issue, recently purchased an XC60 with Volvo fitted 13 pin electrics, plug it into the van, nothing, dead as dead can be, ok with the previous towcar, connect up to a trailer board it works fine, connect to the van,  nothing.
    Van has been tested no fault found, plug another towcar to it, works as it should.

    Also plugged a Sealy VOSA approved MOT 13pin tester, all the LED’s rhythmical pulse so basically MOT fail.

    Been back to the dealers, no fault found. Going back to the dealers again this week.

    On another forum it has been posted that another two members have similar issues, one connected to his van, his was dead, messed about with the 13 pin plug, saw another caravannner with an XC60, spoke to him and his was dead, went back to his own plugged in again and worked fine as did the other one. There does seem to be an issues with XC60’s and 13pin electrics.