V70 Ph1 towing wiring

[CPH]

Thanks Ed, but I've wussed out and have booked the car in at Bank Farm Trailers in Newport this coming Friday to have the electrics fitted properly.

At least I won't have to turn the air blue trying to do it myself, although I'm sure it's not that difficult. Plus, if it's going to be as cold as it has been today then I'd rather not be fettling cars anyway.

[mikealder]

I will add some instructions to this thread after tea as I have worked out where to splice in to the wiring to avoid upsetting the bulb fail detection circuit which might be handy for the place you are taking the car to, if they simply splice in to the wires going to all the bulbs in the rear cluster the extra load of the trailer bulbs will mess up the detection circuit and put the bulb fail light on the dash all the time a trailer is plugged in - Mike

[mikealder]

LH Indicator Green wire at rear of light cluster.
RH Indicator Blue/ Green wire at rear of light cluster.
Reverse Blue wire at rear of light cluster.
Rear Fog Violet/ White wire at rear of light cluster.
Brake Yellow wire at pin 12 of bulb failure detection unit.
Tail White wire at pin 3 of bulb failure detection unit.
Earth take to earth stud just below either rear tail light clusters.

The bulb failure unit is located under the LH side load deck base which simply pulls up, by attaching the Brake and tail light trailer wiring to the input side of the failure detection circuit you wont upset the bulb failure light on the dash. The black plastic box is about the same size as a packet of 20 fags and has a 14 pin connector going to it.

To avoid the use of a relay for the indicators make sure the indicators onthe trailer of of the LED type without integral balast resistors as this type of "bulb" draws such a small amount of current it will have a marginal effect of the flash frequency of the indicators.

As for fridge power/ caravan battery charging make sure they fit a split charge unit as the car battery needs to get enough charge before the caravan battery is switched in - Mike

[xc70jason]

Hi Chris,just one thing to remember on having a 13 pin (euro) socket is,it'll be part of the MOT!.

The 7 pin isn't.

Jason

[upv5]

The 850/V70 do have a socket for the towbar wiring but only if you use the genuine Volvo wiring loom. This has a double sided plug which goes into the bulb failure device and the original loom plugs into the reverse side of this special plug. Power is picked up from 6CD player loom in a similar way. Indicators & reverse lights connect to the available spades in the rear light units.
No cutting, splicing or scotchlocks required. The Volvo loom comes in 7pin, 2x7pin & 13 pin variants and fog light off relay is also available. No software upgrade required for 850/V70.

When I bought it a few years ago, the full 13 pin kit costs around £70.

John

[CPH]

Originally Posted by xc70jason

Hi Chris,just one thing to remember on having a 13 pin (euro) socket is,it'll be part of the MOT!.

The 7 pin isn't.

Jason

Thanks for the heads-up Jason, didn't know that. I will still plug ahead (no pun intended) and go for the 13 pin electrics - I cannot stand the 7n and 7s sockets by comparison.

[CPH]

Originally Posted by mikealder

LH Indicator Green wire at rear of light cluster.
RH Indicator Blue/ Green wire at rear of light cluster.
Reverse Blue wire at rear of light cluster.
Rear Fog Violet/ White wire at rear of light cluster.
Brake Yellow wire at pin 12 of bulb failure detection unit.
Tail White wire at pin 3 of bulb failure detection unit.
Earth take to earth stud just below either rear tail light clusters.

The bulb failure unit is located under the LH side load deck base which simply pulls up, by attaching the Brake and tail light trailer wiring to the input side of the failure detection circuit you wont upset the bulb failure light on the dash. The black plastic box is about the same size as a packet of 20 fags and has a 14 pin connector going to it.

To avoid the use of a relay for the indicators make sure the indicators onthe trailer of of the LED type without integral balast resistors as this type of "bulb" draws such a small amount of current it will have a marginal effect of the flash frequency of the indicators.

As for fridge power/ caravan battery charging make sure they fit a split charge unit as the car battery needs to get enough charge before the caravan battery is switched in - Mike

Mike,

Thank you once again, I shall print off your instructions and take them with me to the place fitting the electrics!

Cheers,

Chris

[gizmo9]

Originally Posted by mikealder
LH Indicator Green wire at rear of light cluster.
RH Indicator Blue/ Green wire at rear of light cluster.
Reverse Blue wire at rear of light cluster.
Rear Fog Violet/ White wire at rear of light cluster.
Brake Yellow wire at pin 12 of bulb failure detection unit.
Tail White wire at pin 3 of bulb failure detection unit.
Earth take to earth stud just below either rear tail light clusters.

The bulb failure unit is located under the LH side load deck base which simply pulls up, by attaching the Brake and tail light trailer wiring to the input side of the failure detection circuit you wont upset the bulb failure light on the dash. The black plastic box is about the same size as a packet of 20 fags and has a 14 pin connector going to it.

To avoid the use of a relay for the indicators make sure the indicators onthe trailer of of the LED type without integral balast resistors as this type of "bulb" draws such a small amount of current it will have a marginal effect of the flash frequency of the indicators.

As for fridge power/ caravan battery charging make sure they fit a split charge unit as the car battery needs to get enough charge before the caravan battery is switched in - Mike

Hi Mike, pleased I happened across this post.. worked great for me. apart from the right hand tail light is not working, this may be the bulb! although I noted that on the 12n plug there is a wire for left hand and right hand but there's only a connection for left hand tail light on the above, so I'm thinking maybe the fog or reverse is possibly wrong? I'll look into it.. but that said it saved me lots of hassle, great job buddy.

[mikealder]

The connection for the tail lights needs to be spliced to both the left and right tail lamp bulbs - Mike

[gizmo9]

Thanks Mike.. silly me, that makes total sense now you mention it. Thanks for putting me straight on that
Cheers buddy.
Carl.