Electrical Mystery

I have a bit of a nightmare, hope someone can help?

When my 2009 Nuevo is not in use I have it on mains hook up at home. I hadn't used it for a couple of weeks and noticed the main control panel was completely dead. The only way I can get it to operate is to start the vehicle then it operates fine and we had no problems over a long weekend away when it would have been charging from the vehicle battery. Van has not been used for 2 weeks again, has been on hook up and same issue all over again.The leisure battery was replaced very recently and the habitation battery is showing 13.8v when the panel does work. To add to the mystery the red charging switch on top of the PDU 4m is not lighting up. My assumption is that this is some sort of charging problem but not sure where to start?

Possibly worth mentioning a couple of months ago the fridge kept blowing fuses so I had an engineer look at it, he wasn't sure if the terminal block in PDU was the issue as fuse was loose and getting hot, so relocated that fuse to a separate holder on side of PDU and replaced the fridge element no blown fuses since then but now I have the 12v charging issue, not sure if there is a connection? Pun intended!

Any help much appreciated.

Type in battery in the search box, you might find some info that may help, until someone can advise you later.
Boaby

As a first step I would measure the voltage with a meter at the leisure battery terminals while on hookup and see whether there is an output from the charger.

You should see around 13 volts

Hi Rubi's Dad,

Interesting that you have no power to the board when at rest after a break.
Then, when you start the engine, you get the D+ signal - over goes the relay(s) and everything then works properly. Engine off - and all OK again (for a while.............).
It sounds like the relay normally closed contacts are giving up. These are the relays that are hanging in the loom down the side of the battery.

You should note that these MES panels are prone to spurious readings - especially if they have suffered from a low voltage situation.
The trick is to remove the hab battery neg. or 30a fuse in pos.- slowly count to ten - reconnect.
This forces a hard reset on the board.

Derek

Thanks all so far.

From my basic investigations what do I know for definite?

I know the almost new hab battery is dead and the only way to get life into it is fire up the vehicle.
I know all fuses are ok including main 50amp fuse to the hab battery
I know the electric hook up is all ok
I know the charger light on PDU will not come on
I know if I turn the engine off the hab battery begins to lose charge

So it is clearly a charging issues. Possibilities?

It is a relay problem, can they be tested?
The charger has had it, does that mean new PDU?
Did the guy who fixed my fridge muck something up ?
Wrong kind of Northern electricity?
Leaves on the van?

Answers on a postcard please 

Do the 230V sockets work on EHU?

Yes they work ok

Is there any output from the charger to the hab battery ?

We need the answer to Willy's question.
Just 'cos the charger light doesn't come on, doesn't necessarily mean the charger isn't working.

"...Did the guy who fixed my fridge muck something up ?..."

Could be.........hence the fast discharge rate when you turn the engine off.
With the fridge on 12v, does the indicator light come on only when the motion sensor sends the relay over and also retracts the step?
Moreover, does the indicator light go out when the engine is switched off?

Derek

Thanks Derek & Willy

The fridge has been turned off while on hook up so that should count that out as a reason for fast discharge. It operates as it should on 12 v while vehicle is in motion, indicator lights and step behave as they should.

As for output from the charger I am not sure how's to tell as I can only get a reading with engine running. As soon as I turn it of the reading plummets

But, do you get a charging voltage at the battery while on EHU?

Questioning if I am reading the meter correctly as I appear to be getting 2/3 v on EHU?

Rubi's Dad wrote:Questioning if I am reading the meter correctly as I appear to be getting 2/3 v on EHU?

On the battery terminals? (Just to check too, you're on the correct DC range?)

Yes on the terminals. Photo of meter attached

Your meter is set on the wrong range - it needs to be pointing at the 20V range at top right 2 'o' clock on the meter - right next to the yellow button

Ok thanks. Have switched to 20v range and I get a reading of 2.9v at the terminals on EHU .

Then the mains charger isn't working.

Probably either because it has no 230V supply at its input terminals (bearing in mind that you say the 230V sockets are working, so there must be a supply into the van) - Or - because it has failed.
The fact that there's no red light on the charger appears to be significant, supporting this suggestion.

This probably means that your 'new' battery is now knackered if it has been discharged to that low a voltage several times, and it's why the control panel only works with the engine running, because there's not enough hab battery voltage to power it without.

You need to find out why the charger isn't working. (pity you don't live nearer, or I'd have a look for you)

Someone recently had a very similar problem, which turned out to be loose mains wires in the back of the charger unit, but I would NOT recommend that you investigate this yourself without a full understanding of exactly what you're doing.

Really helpful and all makes sense . Hopefully the hab battery isn't knackered yet as it will charge from the vehicle and hold a charge over a long weekend away.

Will PM you too - Cheers

It may, possibly, be acceptably OK, but it will have had its capacity and longevity reduced by being so thoroughly discharged, especially if it's more than once or twice.
You're talking to someone here who will try to extract the last ounce of usefulness from a 12V battery before giving up, so I'd probably give it at least a chance too.

PM me again, second and third PMs were repeats of the first.