When I fitted a towbar, I used a bypass relay box.
It helps to stop the lights dimming by getting power from the battery.
There was already a single wire on the right side from factory, that provides the power.
Something like this:
http://pages.ebay.com/link/?nav=item.vie...69&alt=web
Not sure what the requirements are exactly for MOT but I think a bypass relay is needed, or maybe this is for newer cars only?
It helps to stop the lights dimming by getting power from the battery.
There was already a single wire on the right side from factory, that provides the power.
Something like this:
http://pages.ebay.com/link/?nav=item.vie...69&alt=web
Not sure what the requirements are exactly for MOT but I think a bypass relay is needed, or maybe this is for newer cars only?