Leisure + Starter battery wiring - crash course please?

[agentdagnamit]

Hi. Looking for some advice.

We have a Bongo with the usual leisure and starter battery combination, plus a CF9 Zig unit. There's a fridge, stereo, cabin lights, cigarette chargers and LEDs that run from the power sources.

Recently the starter battery lost its charge after only a few days of non use. Never happened before, but it does seem to be the original jap battery.

I've just tried to establish what runs off which battery, and now suspect that all of the above will run from either, regardless of the "Car" or "Caravan" selection on the Zig. eg: I disconnected the leisure, and found that the fridge will still run, which surprised me (this would drain the starter pretty fast wouldnt it?).

Is there a normal way of setting up the circuit? I'm hoping the devices would use the leisure battery if it has enough charge, secondary would be the starter, but the starter would be protected from running dry in that situation?

Also, I measure the current across the negative starter terminal when operating the fridge with the leisure connected, and the starter seemed to be drawing about 20 amps. Would this actually be being supplied by the leisure, but measurable across both (if that makes sense?).

thanks
Stu

[g8dhe]

Right lets start from basic's!

Normally the LB is charged from the alternator using a Split Charge Relay (SCR), this relay operates to connect the SB and the LB in parallel when the alternator is running so that both batteries will charge together. The wiring for this is usually easy to spot under the bonnet, as there will be a cable running from the SB via a fuse (20-80Amp) to a "module" that is the relay, there will then be another cable from LB via a similar fuse to the module as well. There will be at least an earth connection from the relay as well and possibly one other wire depending on how the relay is switched - sometimes a signal from the ignition switch (hence the extra wire) sometimes by sensing the voltage (Voltage Sensitive Relay).

The next step is to provide power to all the items you want running from the LB, this is often in the form a an extra fuseblock connected to the LB +ve terminal with wiring going down to the original fusebox to pick up and replace 4 fuses in the top row of the fuse block down by the drivers knee. These can often be seen plugged into the front of the fusebox, sometimes they are wired to the rear but the fuses will not be inplace which ever method is used;


Now not all conversions use the above format some do their own thing
Often the fridge is wired separately back to the LB, or use the connections on the CF9 Zig unit.
The CF9 Zig is not really meant for Motorhomes - its meant for Car and Caravan - and is complete overkill for a Bongo, and hence tends to get wired in some strange configurations, including doing away with a SCR above and simply rely on the user operating switches everytime they start/stop to connect the battery in parallel and then disconnect them - forget this and you have a flat LB and SB

To be certain about the way you need to use the CF9 you need to know for certain just how it has been wired up, do you have a SCR under the bonnet and do you have an extra fuseblock on the LB is the first two questions ?

[mikeWalsall]

This is a very simple kit to wire .. blinds .. interior lights .. ciggy / lighter .. radio (with it's own on / off switch) .. or what ever .. (as long as the wire / fuse is within there amperage limits) directly to the leisure battery ..



The main (thick) wire is connected to the leisure battery positive (+) terminal .. the harness with the thin wires is fed through the bulkhead (normally where the clutch pedal would have been) ..

The fuse to to the blinds .. interior .. light .. ciggy socket or what ever in the Bongo box is taken out and one of 'tabs' of each thin, separately fused wire, is the 'plugged' into the items 'feed' in it's place ..

[cmm303]

Maybe first confirm that you REALLY have an LB and an SB.
Bongos fitted with a winter pack originally had 2 x SB. How to tell? Do you have a rectangular switch with a gearbox legend in the cluster above your right knee? If not you don't have the winter pack and you have an LB and can ignore this post! If you have this switch, the next step is to confirm that one of the SB has been disconnected and wiring replaced with the config described by g8hde.

Additionally the LB should have leisure on its labels but still best to confirm its been wired as a LB if your Bongo has had the winter pack.

[mikeWalsall]

Reading through this posters request .. I would say they definatley do have a leisure battery fitted .. and not a Northern spec with two starter batteries and a quick engine warm up devise on the exhaust ..

[cmm303]

Reading through this posters request .. I would say they definatley do have a leisure battery fitted .. and not a Northern spec with two starter batteries and a quick engine warm up devise on the exhaust ..

sorry! Must have missed something.

[agentdagnamit]

Definitely a leisure battery. The conversion was done by JAL Imports last year, including the Zig.

[scanner]

If the conversion was only done last year, I would suggest going back to JAL, ask them to explain what it is meant to be doing and to check it is doing it.