Technical 2016 Ducato Alternator failure query

[FiatATImala]

My Fiat Ducato based Motorhome, (2.3L, multijet 180, 2016 build) a short time after starting brings up the battery icon on the display. Engine scan shows nil error codes, the battery is only 2 yrs old starts the engine as normal and holds 12.8v overnight dropping to 12.1v after starting and running with no sign of alternator charging. My assessment is alternator failure after various voltage checks but am I being fooled by an ECU or computer issue?

 

[Communicator]

I do not think that any sensible answer to the question is possible without knowledge of the starter battery terminal voltage, with the engine running. Preferably readings taken before and after the battery alarm is initiated.

 

[the green vanper]

I'd also check the earth / ground points all around the van, Ducatos + siblings are known of getting bad contacts in those places.

The most problematic one is the one behind the left headlight. Don't forget to check the one directly by the battery. Check also the battery terminals if the cables fit firmly and there are no too much oxidation on them. If so, use carefully some boiling water to dissolve them.

+ the positive cable on the alternator side.

MES and other scanners should also provide information on charging voltage. Alternatively you could use some kind of voltmeter (I've got one which is a USB charger at the same time) plugged in my cigarette lighter socket all the time.

 

[Communicator]

I am sorry to disagree, but the only way to accurately check the battery terminal voltage is by connecting a voltmeter directly across the battery terminals. If the measused voltage is deemed insuficient, then is the time to look for causes.

The most important earth or chassis connections in the charging path are, as mentioned above, the battery to chassis connection, and that which has been overlooked above, the notorious engine block earth strap, which can suffer from concealed internal corrosion.

 

[the green vanper]

I am sorry to disagree, but the only way to accurately check the battery terminal voltage is by connecting a voltmeter directly across the battery terminals.

Yes, of course. If you want to mesure battery voltage. I'd even say, that it'd be better to disconnect the negative cable to be sure there's no extra load from the electrical installation. Before disconnecting the battery be sure to respect the order of actions as described in the user's manual to avoid the airbag module problems.
But FiatATImala thinks the alternator is not charging properly. Again, it could be mesured directly on alternator's terminal + the earth. But during normal usage or just to observe what's happening, such voltmeter is a good help.

In my Ducato I've found that the trailers' hook module is constantly under voltage and it can discharege the battery in around 3 months if I don't drive the car. Even though the battery is new and the charging is correct. I've put a switch on the cable, so I can switch the module on only when I need it

 

[FiatATImala]

Thanks for the replies with your suggestions. I'm a retired Tech/Tech officer and have an idea of things electric. In trying not to make my post too long and complicated maybe I should have included more detail, apologies. My Motorhome is an Autotrail Imala 730.
I'm stuck at Georgetown Queensland Australia in an almost remote area so don't have facilities I'd have at home. I have checked all the basics such as ground points, none loose or broken but difficult to remove and check actual mating surfaces, but I did use a solid jump cable clamped between engine and chassis to bypass which made no difference, also the starting circuit is coupled in with the charging circuit and if grounding straps were faulty I'd expect it to affect starting being much higher current.
Battery voltage is normal around 12.8v at rest and only drops to 12.5 with headlights on so I don't suspect it. At the time I checked the battery voltage across its terminals (I have an accurate multimeter) it read 12.4v after starting, then no change noticed for about 3 min when the battery symbol lights. I read this to be a built-in delay after starting while the alternator spins up to prevent a sudden false indication. Basically, its nil output from the alternator. Tomorrow I intend to find the Alt D+ lead which is the excitation winding to see if it has voltage applied, it connects to the body computer for excitation and monitoring as best I can find out.

 

[the green vanper]

If you haven't, just to be sure, check this fuse box, it has a fuse for alternator and starter motor. I know that your van is starting, but it's worth a try

After connecting 220v inverter directly to fuse box all electric went down. | FIAT Motorhomes / Campervans

Hello everyone, My name is Netanel and I'm from Israel. I bought Fiat Ducato (X250 chassis) and build a motorhome on that chassis. Everything went fine, until one day I wanted to install second inverter for my 12v car battery (I also have leisure 24v 250amp battery). I connected it by mistake...

www.fiatforum.com

 

[Communicator]

I cannot find any logic in post #7 above, however I will give it the credit of causing me indirectly to suggest another possibility.

On the x250 and later models the alternator output (B+) is connected to the battery fuseboard via the starter motor. Is it possible that there is a loose connection either at the alternator, or starter.

Disconnect battery using correct procedure before investigating.

 

[the green vanper]

I cannot find any logic in post #7 above, however I will give it the credit of causing me indirectly to suggest another possibility.

Two heads are better than one

 

[FiatATImala]

Based on the replies I've double checked all fuses. I contacted my FIAT Service Centre in Tasmania and they agree with my findings that the alternator is at fault. I was trying to ascertain whether the body computer interface may have some bearing on the issue and fooling me. The local mechanic here in Georgetown Queensland has procured the replacement alternator and scheduled for Tuesday 13th to install; fingers crossed. I'll post the outcome.

 

[FiatATImala]

Things have turned pear-shaped.
Last Tuesday the old alternator was removed after wrecking most of the front of the vehicle to access it, wheels removed, drive shafts, steering box and hydraulics, wishbones, the works looked like a bomb hit it. Then to find the Repco/NAPA replacement was not correct even though matched to my vehicle model and VIN by them. Mounting points were different, pully wouldn't line up with belts, and pulley was for 6 rip belt not 7 rib as needed. So a mess ...
The mechanic rang around various sources and supply always seems an issue, none in Australia quoted 6 to 12 weeks delivery. The original is a 150 amp Bosch alternator specifically used on Fiat's intended for use as motorhome.
Sadly the mechanic couldn't leave my MH in bits as he needed his workshop for other jobs, so put it all back together that night as he had urgent work next day.
When the mechanic finished up and was bleeding the steering system which involves turning the steering wheel to opposite locks for a self-bleed, in the process he heard something like breaking plastic sound behind the wheel horn and the Airbag warning light is now up. Apparently it’s called the 'clockwork spring' and is a coiled up flat cable from ECM to steering wheel controls.
Next day when I took it back to the van park there is also an ESC alarm! The guy is a diesel mechanic and didn't want to get involved with the electricals or air bag. Apparently you must be licensed to play with Air bags?
I rang Williams Auto Electricians in Cairns re rebuilding the alternator but they also say components are an issue and reluctant to take it on and they definitely wouldn’t get involved with the air bag or ESC system. I contacted the Fiat repairers in Cairns and they said they are flat out through to end of July the earliest they could look into it.
There is a European vehicles service centre which includes Fiat Professional in Townsville who seem happy to do a diagnosis and see what’s involved for us. Pretty unsafe to drive and I'd have to keep the engine battery charged, so RACT have organised 'Reardons' to backload on a flat tray the 540km plus to Townsville next Tuesday. Oh dear

 

[Communicator]

FiatATImala,

I am sorry to learn the recent developements in your problem.

In post #2, I suggested that the battery terminal voltage should be measured with the engine running.

It seems from your post above that your mechanic was lowering the engine, in order to access the alternator.

Forum member @Anthony489 has recently posted a guide to replacing the alternator on x250, which involves removing part of the exhaust. I am wondering whether this method could be applied to your x290?

As some consolation you may have been saved from many other problems. It seems that some replacement alternators will not communicate correctly with the BCM, making an OEM replacement part essential.
This thread, while not relating to a Ducato, is well worth browsing. A test procedure is detailed at post #47.
Also there are mentions of resistance readings between D+ and earth on OEM alternators, and Fail on Fit replacements. The D+ to earth resistance must be low enough to pull the BCM output low, to initiate excitation from the BCM.

 

[the green vanper]

After a really quick check it seems that even 150 A Bosch alternators for a x290s differ. I found one with 6 rib pulley and another one with 7 rib puley. The Fiat and of course also Bosch number also differs.

It is possible there's some kind of error, but just make it check twice before placing the order.

 

[FiatATImala]

The Townsville Auto Group (TAG) replaced the alternator with same part number of the original and all OK. I have driven for 2 weeks now and given it a good test. As a result of the 'Bush' mechanic upsetting the steering 'clock spring' module which includes the stalks for turning indicators/lights, cruise control and wipers was replaced and fixed the airbag and ESC warnings. Dam expensive but I had no option being away from home touring mainland Australia. I have the faulty alternator and steering module to checkout when I get back to Tasmania in about 2 months.