Battery Terminals

[wotme]

I thought it would be easy enough to identify the negative terminal of the starter battery on my Fiat Ducato but I cant see anything that resembles an earth connection. I would love to go on a run to charge the battery but I have no choice other than parking it on grass which is too wet at the moment to get traction so I need to use a charger. Can anyone help and tell me if the negative terminal is nearest the front of the vehicle

 

[Geo]

Connect earth to any metal part of engine or body it will save struggling to find earth
I assume you have found the live connection away in middle of engine no need to go anywhere near battery

 

[LesW]

A multimeter would normally tell you which is live/earth.

 

[Landy Andy]

What age vehicle would help.
On the later models you can use the jump start points under the bonnet.

 

[wotme]

I don't think it has jump lead points under the bonnet as its 2007 getting on a bit.
In the photo it shows three cables coming from the terminal nearest the front of the vehicle.
The other terminal has a multi-cable connector plate which I would take to be positive but its the number of connections on both terminals I find confusing. Photo coming soon

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[tacr2man]

That pic doesnt show anything conclusive . Near one of termionals on battery top case should be a - or + sign the minus should go as earth .
If you cant find then look for which terminal is connected to chassis that is negative

 

[wotme]

 

[Landy Andy]

The terminal at the front is the negative, in my opinion.

 

[wotme]

What the hell is going on, it shows I know as much about posting as I do auto electrics
One of the cables obviously goes to earth which I was hoping to find but like I said its not easy to trace.
I was hoping someone could tell me if positive or negative is nearer to the front of the vehicle

 

[autorouter]

On the negative battery terminal, all those terminals are connected to each other, so you can clip onto any of them, it doesn't matter.

On the positive battery terminal, the smaller terminals are connected by fuses, so you have to be very careful exactly where you clip onto it. Better to use the jump start terminal. Unfortunately I'm no help on that because I don't know where it is.

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[Landy Andy]

Negative is at front, nearest bonnet. Positive at rear, under windscreen

 

[gus-lopez]

The 'red' one at the back is +. The 'black' one at the front is -.
On either of them near the terminal will be a moulded + or -.

 

[thebriars]

I'd forget about which terminal is which and look at your charger. If it has a light to show when incorrectly connected, clip on and you'll soon find out.

If it does not indicate a reverse polarity, bin it and buy a new smart charger. They're dead cheap these days.

 

[Northernraider]

As others said the negative is closest the positive is at the back ....same as it is on mine also

 

[Jev88]

Negative front - and i highly recommend you get a little multimeter..... trust me, you will need it for other jobs.

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[HandyAndy]

Also need to visit specsavers...

 

[Spanner]

The first three digits on the battery label state 019 type so as others have said the Negative terminal is nearest the camera lens / front of van
The Negative battery post is always smaller in diameter than the Positive post.

 

[Vipar]

A bit of wire with a 12v bulb in the middle I have a inline fuse in mine, put 1 wire on a terminal and the other on the other terminal the bulb should light. Now put 1 wire to the chassis if the bulb lights the wire to the chassis is the negative/ earth. Used this for years worse case you will blow the fuse as it arks.

 

[wotme]

Thanks guys for your support

 

[Gromett]

I have the same model. The big plate at the back is positive.

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[richard burkinshaw]

Now that's sorted can anyone help me on a related question please.

Which are the 3 input/outputs on this 2010 Ducato 3 litre where the battery is under passenger's feet. see photo attached.
they have 50, 50 and 70A fuses.

looking to identify from someone who already did, before i start work.
- alternator feed in
- feed out to split relay / leisure battery midway down the van.

also I would be interested to see a photo identifying jump start connectors under the bonnet someone mentioned.

thanks in advance for your help.

Richard

 

[richard burkinshaw]

photo

 

[gus-lopez]

photo

View attachment 347760

I'd be concerned that the one on the right is or has been drawing high current & has melted in to the insulation as well as the sleeving looking burnt/overheated

 

[Wagoneer]

photo

View attachment 347760

I have a 3 litre X250. My fuses left to right are 70/50/60 amp. You should have two other larger fuses 150amp and CAL 5 (starter motor).

On mine the feed to the split charge is via a separate feed (with dedicated 25amp fuse) from the common plate with all the Fiat fuses (as shown in your pic).

This Fiat X250 wiring diagram may help:

 

[Wagoneer]

The wiring diagram attached above doesn't replicate exactly the wiring on my 2009 X250. However, it gives you a general idea of the basic system.

The jump start +12v feed can be found on the right side of the engine above air filter housing. It is a housed in a black flip-top box. Connect the negative to a convenient earth on the engine (say, engine lifting lug).

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[richard burkinshaw]

Thanks

A slightly wider view shows all connections to starter battery +ve

CAL5 can be seen.
There's no more connections than these.

Good call by Gus Lopez re overheating, which is where the cable passes through foam seal. Another reason for upgrading (and cutting back the foam.)

Does this suggest that this is the alternator feed being the one that overheated (the highest current loading as it is charging the starter battery, feeding in/out of the plate to the van lights/blower, and feeding in / out of the plate to the leisure battery? )

Richard

 

[pappajohn]

I'd be concerned that the one on the right is or has been drawing high current & has melted in to the insulation as well as the sleeving looking burnt/overheated

It looks more to me like something has been pressing on it and rubbing slightly.
Possibly the battery cover plate.
It's just in one small area and right at the edge of the battery compartment.
Reposition it to the other side of the raised lug next to the other two.

 

[Wagoneer]

The thick red cable from the CAL 5 mega fuse goes to the starter motor (via the +12v jump start tab). Another thick cable then goes from the starter motor to the alternator.

This 3D view of the wiring harness may help:

 

[richard burkinshaw]

What an excellent 3D diagram. Thanks Wagoneer.

So alternator charges battery via starter motor cable.

Leisure battery split offtake will be odd one out from the plate, probably the thermally damaged one. I have a DC clamp ammeter on its way to check. (I am still 150A fuse short versus 3D diagram on my B1 + plate?)

However, I am minded to run a direct parallel cable from alternator second stud to split relay input, bypassing the starter battery.

Any thoughts?

Cheers

Richard

 

[Wagoneer]

Confirm, yes the engine battery is charged from the alternator via the starter motor. If the OP is experiencing poor charging it may be prudent to clean up the starter motor connections to ensure there is no earth leakage.

I attach a pic of my battery connections. The blue cable (via 25amp separate fuse) goes to the CBE 12v distribution box which houses the split-charge relay.