Fiat Ducato 2008 Motorhome Battery Disconnection Procedure

[PNAJones]

Hello,

I have been looking around various questions and info on Fiat Ducato based motorhome battery disconnection, and am none the wiser.
The Speedometer has not worked since we collected the van from its previous owner, I am going to send the speedo cluster away for diagnostics. (fuel gauge, rev counter and temperature work fine, as does the LCD display).
I have read that when disconnecting the negative terminal on the service battery it is also advisable to disconnect the leisure battery at the same time, before disconnecting the speedo cluster.
The repair is likely to take a few days during which time the battery will remain unconnected, and will not affect the Body Control Module as they are designed to be inactive at times when servicing etc. So my question is what is the preferred procedure for battery disconnection and reconnection?
Thanks in advance

 

[Bandos]

You will find the some info here

Starter Battery top up or removal /replacement

To avoid any problems with spiked or corrupted ECUs there are number of precautions to be taken. The SRS ECU (airbag), in particular, seems fairly prone to this and damage is often blamed on incorrect battery disconnection or jump starting...

www.fiatforum.com

Basically

The problem is that the system need to shut down and start up in an organised way, if the battery power is low or intermittent during this shutdown, memory may be corrupted or the communication process between modules confused. It's the air bag computer that is most likely to fail. It's the door switch that initiates the start up or shutdown of the van electronics.

To disconnect the engine battery.
In a camper conversion, first disconnect any link between the engine battery and any B to B charger/VSR/solar charger.
Remove battery cover.
From inside the van close all doors and windows, but don't lock the van with the remote.
Remove the ignition key.
Wait a couple of minutes.
Disconnect the negative terminal first, then positive if removing the battery
Its now safe to open the doors!


To reconnect the battery.
Close all the doors and windows.
Ignition key removed.
From inside the van reconnect the battery, negative terminal last.
Wait several seconds and turn the ignition on.
Wait a further minute before activating anything else.
Open doors.
Reconnect any camper circuits.