Fitted the towbar and have the electrics socket connect and the flex inside the car, next problem how to and where to tap into the electrics!?!

It's a second hand kit so I have a load of splice connectors and a relay box – I think I can work out the lighting side of it but don't where the relay should go?

Any clues? Otherwise it £80 for a new wiring loom!

Cheers
Moff

Which golf is it, I'm intrigued as I have a Mark 4 which i put the tow bar on and never got round to wiring the socket. I wondered if it would wire into the connectors on the rear of the nearside light cluster?

google search for 7 pin towing electrics to confirm pin alocations and wire colours. Trace the wiring back from each light to a point where they come together as one loom and break into the wiring at this point this makes sure all the connections are in the same place for tracing faults later. If it is a newish car you may be able to locate a socket that they use for oe fitment of towing electrics use this if possible. Dont bother with the relay cos it is most likely just the audible warning to let you know you are towing or using a trailer board. Use a trailer board to confirm you pick out the right wires if you dont have a tester. The sounder is just 4 wires, two from the socket l anrd r indicators the other two wire to the indicators on the car and there might possibly be an earth to connect. Please solder the joints if at all possible those scotch lock type things are just shite and a pet hate of mine

All of the towbars I've had, we've just put the relay just behind the light cluster where we tap into the wiring for the electrics.

Or as sturmey says its only normally an audible warning relay, just junk it!

Just a note some cars dont like you to just tap into the light wiring these are usually cars with can bus system (signal sent down 1 wire to a box that sends a feed to correct bulb. As said earlier use the manufacturers socket if it has one.

Dedicated wiring kits aren't always a case of locating a secret plug, they're sometimes as complicated (if not more so) than wiring in a generic kit. I'd be very tempted to fit a smart 7-way by-pass relay. Its a doddle to fit, & will protect the car if its either a Bus system or has bulb failure monitoring. Even cars now 10yrs old are pretty complicated in terms of wiring etc.
As for locating all the wires, pick up an electrical tester, mine was £5 from Wilko's. Just set it to the relevant DC voltage & probe each pin on the lights with the relevant circuits working. It its just the std (7N) socket its easy. If you have to wire in a 7S socket you have to run wires from the battery along with a caravan fridge relay. And despite the bad press, if used properly Scotchlocks are fine. I've used them for years without any issues.

The car's an 04 Mk4 Estate, all the bit were taken from someone else's company car that was handed back, so I've got all the bits including the Scotchlocks and the relay.

I think i've sussed the colour coding for the wires, just need to find a place where they are all together.

There's a loom that runs across the rear under the boot sill trim, but only seems to have the right hand feeds, otherwise would be an easy place to tap into. The wiring around the light clusters seems pretty difficult to access.

The problem I have/had with the relay was that the wire colours are different on the input and output sides, with the third cable on one side I guess being the earth. I wasn't sure if the relay was needed, yes its audible, but wasn't sure if it was needed to balance the extra lights connected.

The OE type set up is a loom the runs right and left with individual connectors that go into the back of the light cluster block – this kit is £80, which is twice as much as a paid for the complete tow bar kit!!

Must get it sorted tomorrow/next week as we're off to the Alps.

I'll give it another crack tomorrow, just a bit nervous about tapping in with the Scotchlocks and fubaring it all?!