Thanks Kevin but I am now confused The tow bar was for a caravan You say the missing bulb sensor, why missing, What do I have to do to sort this out or is it OK to leave as is. The fitter did use scotchlocks which I must admit I dont like much
The car's wiring loom makes provision for a bulb failure sensor in the circuit to the trailer lights. It's not fitted unless a towbar is fitted, which is why the brake circuit at the car's towing connector wasn't live.
You now have both the caravan and the car's brake lights powered through the car's bulb failure sensor.
This raises 2 issues which may or may not be regarded as a problem:
1) When towing, you need 3 brake lamp bulbs to fail before you will get any warning in the car. Not necessarily a problem as it's good practice to check all lights each time you hook up anyway.
2) The car's brake lamp bulb failure sensor how has double the current flowing through it because you've added another pair of brake lights. You might well get away with this but you might find the bulb failure sensor fails.
I would remove the scotchlocks and replace with soldered joints, as said. While you're at it, you might as well connect the brake lights to the proper connection on the towing loom and bridge the connections where the bulb failure sensor for the trailer brake lights is. There is info. on here in the electrical section on how to accomplish this, but I will see if I can dig up the HOWTO that I was in the process of writing.
Kevin