just fitted towbar onto my vectra but now i need to do the wiring?

Am in the same boat only I've wired mine up correctly but lights on caravan R dim just wondering is that because I need 7 pin bypass relay my car has the on board comp that tills if a bulb is out

steeky
June 2012

I'm also figuring out the wiring for a Vectra towbar. Mine is the 2002- model. John doesn't mention the bypass relay required for this type of car - without it the car thinks a bulb has blown. I purchased the "12N towing interface relay kit" in a package from TowbarsRus. Its made by PCT automotive - see http://www.pct-automotive.co.uk/Fitting%20Instructions/pdf/ZK3000A.pdf for instructions. You need to allocate a separate fuse to power the relay, and tap into the lighting cables behind the trim in the boot for the individual bulbs. I am struggling with where to take the power from. There is a fuse position in th boot fuse board identified in the manual as "13 - towing equipment" which I presume is for this purpose. Now I need to identify which terminal connects to this fuse using a multimeter. I need some help.........?
I'm slightly upset that neither Vauxhall or PCT are able to give the full intructions - I guess Vauxhall are protecting their own interests and PCT struggle to keep up with the electronics.

Dave A.
July 2005

You need to source the wires going to the tail lights. Purchase a 7 pin plug which will have the information you need.ie. What functions go to what number in the plug. You will need to tap into the original wiring so you can "T" into it. Most towbar installers use "scotch locks" some call them "quick tees". Most of the time you only need 6 core cable as the 7th pin in the plug is for trailer brakes which you may not need. The six you do need is right and left hand indicators, tail lights, brake lights, reversing lights and the earth wire. You may also need to use a test light or multimetre if you are not sure which wire does what function. Otherwise you will need to trace each wire to each bulb to work out their function.

John
June 2005