Issues with DC when connection to car

[RichardW1]

When my van is connected to my car via the grey plug my interior van lights work ok. As soon as i start the car the lights start to flash on and off. This is also affecting the fridge as on long journeys it starts to defrost. This has been an issue for a while but didn’t realise till late last year when using van lights while connected to the car.
Any ideas what maybe causing this.
Thanks Richard W

 

[SteveW77]

B) Sound as if the habitation relay is on the blink, or the 12v supply from the car is intermittent, thereby making and breaking the supply to the habitation relay.
The moment the engine is started the 12v supply to the caravans 12v circuits should be cut off apart from the fridge circuit and battery charging.

 

[RichardW1]

Ive checked the 12v supply from the car and its working fine. Ive looked through my van instruction booklet and it tells me about the habitation relay but not where it is. Ive found what looks to be a relay under the front window. with the fuses for van lights heater fridge ext. Is there a way of checking if they are faulty. Ta

 

[SteveW77]

:cheer: The easiest way is by substitution, I don't think they cost that much. I have known tow bar connections that show a good 12volts, but the moment any load is applied the connection breaks down.

 

[RichardW1]

Hi
I've checked the grey plug, and pin 4 is a constant feed and pin 2(charger) & pin 6 (fridge) works as they should when the ignition is switched on.

I was hoping that lights issue was related to the fridge issue I’ve got of not staying cold on long journeys. Because if the fridge was reacting the same as the lights when the engine was running it would start to defrost. As on a long days drive when travelling in Europe the freezer part of the fridge has started to defrost.

I hoped they both went through the relay and that's where the issue was.
Thanks for your reply`s
Richard W

 

[johnandrew70]

I had same problem with lights and fridge, you could hear the habitation relay clicking in and out at the same time, my problem was the intelligent split charge relay was set too high and as already mentioned was fine when there was no load but went off as soon as there was heavy load.
Get someone to raise the engine speed while you stand in the van to see if it works if so you might need to adjust the charge relay so it kicks in at a lower engine speed also make sure your leisure battery is connected properly as i think on some vans if there is no leisure battery present the fridge wont work, i am sure someone will correct me if i am wrong.

Out of interest what van do you have?

 

[RichardW1]

Hi
i have an abbey 325 2003. will looking your comments and there is a battery connected.
Cheers richard

 

[johnandrew70]

Mine was an Abbey 215 have you checked the fuses for the fridge? also i believe the van/Neutral/car switch has to be on Neutral for the fridge to work while towing and fridge switched to 12v,

 

[Dustydog]

Hi Richard

.

Sounds like a poor earth problem. I suspect the 12s and 12n are using the sameearth point on the car. Check and clean.