towing lights not working

[zeus]

Help!!  i have a 13 pin towing socket fitted next to my detachable thule tow bar. the lights on caravan have totally gone. I have changed all the fuses on my car for towing socket. i have bought a new 13 pin to 7 pin towing cable. i have fitted 2 new sockets on caravan towing leads( N and S type).i have changed all fuses in caravan and still nothing. is it my car or caravan. stuck what to check next. any clues woould be gratefull. oh, car is xf 08 2.7d

karl

[KEN33Y]

Karl, have you a volt meter? If not then I would suggest you get hold of one or a multimeter capable of reading DC Voltage. Turn the lights on individually and measure for 12Volts, you can take the ground reading from either the socket earth terminal or any exposed metalwork on the vehicle (a nut or bolt would suffice) once you prove the ground stick to it and continue to turn the varying lights on one by one. You say that you have changed all the fuses I am confused as to why? Did you check that voltage was at the fuses before changing? have you checked that voltage is leaving the fuses and reaching their final destination i.e. the lights since changing the fuses?

[zeus]

Hi Ken. i have just used a fluke and then gone through each of the 13 pins on the towing socket and i am getting no voltage so it cant be the caravan as it is not getting any power. i have changed the 3 fuses according to the handbook and still no power. i have checked the ommhs of the fuses and they are good. looking at things i have googled, there might be a 7 pin relay with an inline fuse fitted, so i am gonna have to trace that. im not very electrical minded so running out of things i can try before having to go to the garage.  i changed fuses on car and caravan hoping it would be something simple...

[KEN33Y]

Sounds very much like a relay then Karl. The inline fuse will no doubt switch the coil on the relay therefore, closing or opening the contacts within dependant on whether they are normally open/normally closed contacts. You will need to source this fuse and relay to see if voltage is arriving/leaving the relay.