# Any Auto electricans able to advise me - on MH problem



## Doversoul (Apr 15, 2010)

Hello 
Yesterday I went down to where my Luna MH is stored to replace the Sony radio with a new Clarion - I detached the negative battery lead on the 85amp vehicle battery expecting that the Sony radio circuit to be dead. The radio continue to work. And as I had left the Fiat hand book at home, I was unable to trace the fuse to the radio circuit, I couldn't fit the Clarion. However, what I found odd and somewhat worrying was that with the negative battery lead disconnected I was still able to start the Fiat engine and move the vehicle - that shouldn't be possible! Thus, I suspect that the leisure battery 12v circuit (2*85amp) is starting the engine or I have a live chassis, that is incorrecly wired up.
Any thoughts / advice - much appreciated .
Rgds


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## pippin (Nov 15, 2007)

You certainly won't have a "live" chassis if you mean that it is at +12V.


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## inkey-2008 (May 24, 2008)

I would suspect the batteries are link and it must be with a thick cable. Removing the earth should have isolated the vans engine electric's. A small cable would have burnt out or caught fire when you tried to start the van.

Andy


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## gm6vxb (Nov 3, 2007)

Is it an X250, new style motorhome ?, if so did you definately remove the negative terminal on the battery in the floor forward between the drive and passenger seats.
If yes to above, could the radio be wired onto the habitat battery.
Try removing the negative terminal on that as well.

I suspect you have not disconnected the vehicle battery, it is a pig to get to, especially if you have after market carpets fitted in the front.

Martin, GM6VXB


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## gm6vxb (Nov 3, 2007)

ooops, forgot, vehicle battery is either 100 or 110Ah. Either you have an after market battery fitted or you are looking at the wrong one.

Martin.


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## joedenise (Jul 20, 2007)

could be that its been wired to the leasure battery

joe


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## Stanner (Aug 17, 2006)

85 amp certainly sounds like the leisure battery not the main one.

Where is the battery you disconnected located?


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## Doversoul (Apr 15, 2010)

*Motorhome elect problems - answers*

Thanks you for all the replies and my answers to questions raised are below.

1-The Fiat 2.8 JTD is 2005 model - Luna 630 Roadstar MH
2- Leisure batteries are located - 1 under each of the cab seats. 
3- The main battery is connected in the engine bay, that is where I disconnected the earth
4- The leisure battery under the driver seat has a 20amp external fuse, and is connected by a cable that runs under the floor to the LB under the passenger seat.
5- To get to both LB requires removal of the seats. Not too difficult with the drivers seats - 4 bolts to remove , but the passenger seat has a swivel and the a lot more difficult to remove. 
6- The MH has an 1600w invertor fitted to power habitation air con, and is linked , probably to the LB under drives seat - hence 20 amp fuse.

It would seem that all three batteries are linked in parallel - but what the implications of that are for charging off of the alternator/ and the 18 amp on board battery charger - when on hook up - is a mystery to me.

I can fit the radio - when I have removed it's fuse - so that won't be a probelm - I will have to remove all the cab seats and try and understand the wiring.

The possibility that all 3 batteries are linked in parallel, probably expains an alarm that we get when starting the Luna , with the 12v circuits on - 'CAR Lo' - meaning battery low.

I have referred the matter to TC Motorhomes who sold me the Luna but have yet to receive a reply.

Any other advice / comments welcomed

Thanks


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