Tow bar / fridge electrics

[Velcrohead]

I have just changed car and had a main dealer (Ford) fitted removable tow bar with 13pin plug. I did this because the ESP, Parking sensors & fog lights needed programming by a main dealer. My old car had12N & 12S plugs. When I plugged my new car into the caravan all lights work and it powers the interior lights and fridge until I start the car, then nothing works inside the van (even with the rocker switch on "car"). I understand this maybe a safety feature once I am driving but shouldn't my fridge still "light up inside" to show its working when towing?
I got the Ford dealer to recheck the wiring and pin 9 & 10 are both permanent 12v, but I believe only 9 should be and 10 should be ignition controlled. This is how Fords say the towing module works and I don't have a problem with that but could the two permanent feeds be stopping the fridge working with the engine running? Or do I need to make pin 10 ignition controlled?
Help, I am off to France tomorrow and worry about the fridge working when I am towing!

 

[Damian]

Pin 9 should be the permanent live, Pin 10 should be ignition controlled live.
When you start the car engine it triggers the van habitation relay which cute power to everything inside the van except the fridge and battery charging circuit from the car.

The fridge should NOT work on 12v without the car engine running.

The fridge internal light has nothing to do with whether the fridge is working, that light is powered by the leisure battery, which will have been cut off by the habitation relay.

 

[Velcrohead]

Hi Damian, but I thought that by opening the door of the fridge the only way to tell if it was operating was by the light coming on?
So if the habitation relay cuts everything off then can I presume just the battery charging circuit and the fridge work via pin 9 & 10 (12v supply) when I am driving? if so how can I check this out with my multimeter?

 

[Damian]

Quote " but I thought that by opening the door of the fridge the only way to tell if it was operating was by the light coming on?"

No, as said that light along with the fridge electronics are powered by the leisure battery and are independent from the 12v heating element which only works when the car is connected to the van and the engine running.

With a multimeter you should have 12v between pin 9 and pin 13 with the engine off.
There should be no volts between pin 10 and pin 11 until the engine is started, then around 14v

 

[Velcrohead]

Ok, thank you. I would appear I am worrying over nothing then!

 

[Velcrohead]

Ok, thank you. I would appear I am worrying over nothing then!