Electric issues

Fog and reverse not working on the car or on the caravan? If they work on the caravan then all is well, on my car the car's fog and reversing lights do not work when connected by the 13 pin plug as they are not needed when towing.

Why are you switching on your 12V when connected by the way? It's not needed but it's perhaps telling you that your caravan battery is fine but not your car's?

Thanks for replying.

Not working on the caravan (haven’t checked if they work on the car whilst plugged in).

I’ve had the car hooked up to a testing box which worked fine, and the caravan hooked up to a tester which worked.

I thought I had to switch the 12v on to be honest! I guess that’s what happens when a dealer gives you info overload during your demonstration.

My pleasure and no problem. I'm sorry but I'm now out of ideas and it's a puzzle if car and caravan both work with a testing box.

All I can think is that perhaps there isn't a good enough contact between car and caravans leads? Are you twisting the 13 pin socket all the way? A spray of WD 40 contact cleaner won't hurt? 

I'm a bit confused at what is being said. What is the exact problem. What is not working?

It sounds like the van is new to you. Have you had a van attached to your car previously and if so did all work as expected.

The fog and reverse lights on the car should not work when the caravan is attached. They are not needed and if they did then the bright reflection off the front of the van would be distracting.

A test box onto the back of the car to identify what is happening may also not be the way forward. You need to induce a load for some of the circuitry to work and some earlier test rigs do not do this. I had this problem when I collected a new car and I was trying to work out why the fridge was not getting power when attached to the car.

Colin

Hello,

it’s the caravan fog and reverse.

When I purchased I remember the caravan fog and reverse not working. However we hooker up to a tester on site and they worked without issue, was told to get car electrics looked at.

went to where I got my towbar and 13 pin fitted, they hooked up and demonstrated that it all worked correctly including fog and reverse.

but still when my caravan and car are connected, they don’t work on the caravan.

Have you had the car computer system reset for towing?

And do check you have turned the 13 pin plug completely.

Does your fridge get power when towing?

When you plug the caravan in, there is a device, (could be mechanical or electronic, doesn't matter here), that functions to disconnect the car rear fogs and reversing lights. To do this, the towbar electrics fitter will disconnect those lights at the car, and re-connect them to the output of this device. The caravan will take the fog and reversing light feeds from the car directly, not connecting to this device.

Now imagine that the car 13 pin socket has been wrongly connected to the output of this device, and the car lights left on the original connections.

Symptoms.

With no caravan connected, car fog and reverse are fine. Caravan tests fine on a box.

With caravan connected, car fog and reverse continue to function, caravan fog and reverse do not work because the device that should stop the car lights is actually stopping the caravan lights when it energises.

Car on a test box, car fog and reverse work, and what would be the caravan lights do work because the device has not been energised.

That is my euros worth.

Thanks for the input.

So if I test the lights again, but this time check to see if they still operate on the car (whilst connected to caravan) then that would indicate it’s been wired wrong?

Would that issue also affect the vehicle (car) battery connection to the caravan, which would impair fridge operation. 

The feed to your fridge and battery may not have been run to the 13 pin connector on the back of the car. This is common with the likes of VAG vehicles but also effects other makes of vehicle. Unless you the person who originally had the towbar fitted asked the for  this function you may well not have it.

Colin

Thanks to all those who gave advice.

I took my car to a different towbar/electric fitters (I’d taken it back to the original ones for testing and they said no issues)

Well, where do I start.

I paid for Fords dedicated system but a universal kit fitted. It wasn’t earthed properly.

And as to why the fridge, fog and reverse weren’t working.

They weren’t even wired up.

55mins of work and it’s all working.