Checking your Caravan Road lights

Total Posts: 8
Please correct the mistakes below:
Posted: 7 years ago
May I offer some advice ton checking your caravan or trailer road lights:

1. Before setting off, don't just check sidelights, brakes indicator etc separately, check them in all combinations.
2. Get your towcar electric sockets checked at its annual service. This is not routinely done.

I'll explain my experience. We always did a cursory check of the road lights operation before setting off towing, but recently at a Motorway Services a truck driver pointed out that my lights were misbehaving when I braked and indicated at the same time. I thought it was just that I had not plugged it in properly so jiggled the plug and carried on.

To cut a long story short, it turned out to be a faulty earth connection in the car to the black plug. Basically there was no connection to the car earth. (It did not earth through the towball hitch which is metal and connected to the earthed car chassis because the caravan running lights earth is not directly connected to the chassis (75 ohm resistance). I did not get the full story from the mechanic (in Spain this was), but I think it had corroded or burnt out because he said that he had fitted a heavier duty earth cable.

If we had looked carefully when doing individual light checks, we would have seen that the sidelights glowed slightly when the brakes were applied or the indicator put on because it was earthing back through that circuit. Maybe my wife had not been able to se this in the sunlight.

Anyway the lesson is learnt and we now do very thorough checks before setting off!
Total Posts: 155
Please correct the mistakes below:
Posted: 7 years ago
We always check our lights in combinations as I used to be an auto electrician.
It is surprising how many people don't even check their lights when leaving a site, and I have had to tell them they have a break light out.