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loss of 12v supply

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loss of 12v supply Empty loss of 12v supply

Post by CharlieM Wed May 04, 2022 4:04 pm

this is a technical enquiry relating to Nuevo ES SF53 FVB.
Job number 1356
I have lost my 12v power and can not see an obvios reson why.
I turned all the 12v switches off ,
removed the battery terminals ready to swap some internal lights and to add a solar panel. to get access to the leasure battery I unplugged te two relays under te driver's seat and detached  them from the driver's seat trim. No wiring was touched.
The new internal light was swapped and the leisure battery terminals  and the relays reinstated. At this point  12v equipment did not work and despite much wire wiggling has not worked since.
I connected the mains supply this made no difference.
At this point I tested voltages, I have 12v available after the fuse and the voltage is available in the relay socket. Beyond the relays I can find no 12v however I am picking up 0.24v at the 12v socket above the fridge and on the back of the main 12v switch..
just thinking as I type if one of my relays died could the 0.24 volts  be what "leaks" through the relay's resistor??
If you can assist that would be appreciated..

Many Thanks 

Kind Regards

Charles Murray
New Member
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Posts : 1
Joined : 2022-05-04
Location : wales
Auto-Sleeper : nuevo ES
Vehicle Year : 2003

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loss of 12v supply Empty Re: loss of 12v supply

Post by brodco Thu May 05, 2022 4:17 pm

Hi  wave
Have you got a wiring diagram for your particular vehicle, if not you’ll find generic versions here:

[You must be registered and logged in to see this link.]

Don’t worry about them being for the VW version, just look for one about the right date that seems to routhly match yours.

The only relay likely to interrupt the habitation supply is the EMC relay and the supply to the habitation area is via a set of “normally closed” contacts so it’s unlikely to be a faulty relay (unless the contacts have fallen apart internally).

Relay bases are a know source of trouble so it’s well worth a look at the contacts in case removing the relay has broken an already weak one. Fundamentally if you have volts on one side of the habitation relay contacts you should have volts on the other (engine off).
CharlieM wrote:I connected the mains supply this made no difference.
If you have an old style charger it should power the habitation 12V whether or not a leisure battery is present but if you have a smart charger it may not start without a battery connected. I think 2003 is about the time when it may or may not have a smart charger fitted.

Brod  drinksallround

“Everything should be made as simple as possible, but no simpler.”


Posts : 1230
Joined : 2012-07-30
Member Age : 67
Location : Worthing
Auto-Sleeper : Duetto
Vehicle Year : 1997

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