This will help if your wiring for English or European.
http://www.volvoclub.org.uk/towbar_electrics.shtml
sounds like the towing electrics have been wired up wrong
At night the towing vessel should show two white lights on top of each other to indicate that it is towing.
Running lights which should be used when towing to indicate restricted maneuverability
yellow over yellow is a inland towing fellow. this would be a inland towing vessel.
yellow over yellow is a inland towing fellow. this would be a inland towing vessel.
A vessel that is towing another vessel should display yellow lights to indicate its activity. Specifically, the towing vessel must show a yellow towing light at the stern and may also display additional yellow lights to signify the length and nature of the tow. This lighting helps other vessels recognize the towing operation and ensures safe navigation in the vicinity.
Look for yellow lights.
Look for yellow lights.
commercial vessal
Look for yellow lights.
Red lights indicate that someone in towing something. They could be blinking or just a red light.
wire into the tail lights at the back of the car