Fridge not working via 13-pin electrics

idheath · Aug 17th, 2008, 13:13

Hi,

I have a Volvo XC90 with a genuine Volvo tow bar with 13-pin electrics (and a Volvo supplied 13-pin to 2 x 7-pin Y-lead).

The problem I have is that my fridge doesn't work on 12V when towing (this should use pins 10 & 11).

I have checked all the obvious things (connections, fuses etc) and everything seems to be in order. I have also checked the wiring of the Y-lead and it's as expected too.

Having just done some testing with my multimeter (via the 13-pin socket on the car, to exclude any issues with the Y-lead) I have found the following:

Pin 9: Constant 12V as expected (referenced against pin 13 for earth) - Used to charge the caravan battery
Pin 10: Ignition controlled 12V (referenced against pin 13 for earth, not pin 11 as it should be) - Used for the fridge

So, to reiterate, the ignition controlled 12V on pin 10 is there but not referenced to pin 11 as it should be (but to pin 13).

As far as I'm aware pin 10 should be paired with its own earth (pin 11).

Having looked at the Volvo installation instructions here it actually states (on the last page) that pin 11 is not used, which matches with my findings.

This seems to indicate that Volvo have not adopted the ISO 11446 standard correctly (see here).

So my fridge doesn't work when traveling :-(

Has anyone else experienced problems with their fridges when towing or have any ideas?

Cheers Ian

Rooster · Aug 17th, 2008, 14:53

When you fit a 13pin onto bigger cars there is 2 spare wires that arn't clipped into block connecter, one of them gets taped back out of way and other connects to one of other wires to make fridge or charging (whatever way your caravans wired up) work,

I think the wires put to earth to make a second earth in what will be your grey socket to make the in your case fridge work,

The connecter depending on what year XC you have will either be on driver side at rear behind panel just plugged in to a connecter (early models upto 04) or will be on passenger side plugged into trailer module (later models 05on)

it shouldn't be hard to miss all wires in block connecter will be white with numbers on them and should corrispond with number in 13pin on towbar

Clan · Aug 17th, 2008, 14:58

Yes for some reason Volvo do not wire up the fridge as standard on their tow electrics...
If you earth the not used pin 11 to the earth point on the earth bolt on the rear member with a ring terminal the fridge should work ...

idheath · Aug 17th, 2008, 17:50

Thanks Rooster & Clan that's very useful information....

I've found the 2 unconnected wires and will connect the pin 11 cable to a convenient earth point.

Many thanks again :-)

Aug 17th, 2008, 13:13	#1
idheath Junior Member Last Online: Jul 28th, 2022 19:03 Join Date: Sep 2006 Location: Nr. Doncaster	Fridge not working via 13-pin electrics Hi, I have a Volvo XC90 with a genuine Volvo tow bar with 13-pin electrics (and a Volvo supplied 13-pin to 2 x 7-pin Y-lead). The problem I have is that my fridge doesn't work on 12V when towing (this should use pins 10 & 11). I have checked all the obvious things (connections, fuses etc) and everything seems to be in order. I have also checked the wiring of the Y-lead and it's as expected too. Having just done some testing with my multimeter (via the 13-pin socket on the car, to exclude any issues with the Y-lead) I have found the following: Pin 9: Constant 12V as expected (referenced against pin 13 for earth) - Used to charge the caravan battery Pin 10: Ignition controlled 12V (referenced against pin 13 for earth, not pin 11 as it should be) - Used for the fridge So, to reiterate, the ignition controlled 12V on pin 10 is there but not referenced to pin 11 as it should be (but to pin 13). As far as I'm aware pin 10 should be paired with its own earth (pin 11). Having looked at the Volvo installation instructions here it actually states (on the last page) that pin 11 is not used, which matches with my findings. This seems to indicate that Volvo have not adopted the ISO 11446 standard correctly (see here). So my fridge doesn't work when traveling :-( Has anyone else experienced problems with their fridges when towing or have any ideas? Cheers Ian

Aug 17th, 2008, 14:53	#2
Rooster Speed freak Last Online: Apr 3rd, 2020 22:04 Join Date: Nov 2003 Location: Yorkshire	When you fit a 13pin onto bigger cars there is 2 spare wires that arn't clipped into block connecter, one of them gets taped back out of way and other connects to one of other wires to make fridge or charging (whatever way your caravans wired up) work, I think the wires put to earth to make a second earth in what will be your grey socket to make the in your case fridge work, The connecter depending on what year XC you have will either be on driver side at rear behind panel just plugged in to a connecter (early models upto 04) or will be on passenger side plugged into trailer module (later models 05on) it shouldn't be hard to miss all wires in block connecter will be white with numbers on them and should corrispond with number in 13pin on towbar __________________ 04 XC90 D5 --- Big bus 00 pug 306HDi --- Run about 88 pug 309GTi --- Project track car 07 CB600 Hornet --- 2 wheel fun

Aug 17th, 2008, 14:58	#3
Clan Experienced Member Last Online: Today 18:52 Join Date: Jun 2007 Location: L/H side	Yes for some reason Volvo do not wire up the fridge as standard on their tow electrics... If you earth the not used pin 11 to the earth point on the earth bolt on the rear member with a ring terminal the fridge should work ... __________________ My comments are only based on my opinions and vast experience .

Aug 17th, 2008, 17:50	#4
idheath Junior Member Last Online: Jul 28th, 2022 19:03 Join Date: Sep 2006 Location: Nr. Doncaster	Thanks guys Thanks Rooster & Clan that's very useful information.... I've found the 2 unconnected wires and will connect the pin 11 cable to a convenient earth point. Many thanks again :-)

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)