Technical Ducato Random Starting Issues

[AndyFire8]

Afternoon Fellow Ducato owners

We have a 2020 - 2.3L multi jet diesel 160hp with the 9G-Tronic Auto Gearbox Motorhome, we purchased it with only 2k miles back in Sept 2021, everything was fine, we had lots of trips away, then on evening in Dec the following year, we went to start the van, and just got a clicking noise from the starter motor, came back indoors to get a torch and multimeter, only to return and it started on the 1st try… fast forward to the following September, again lots of trips in between, we had the same issue reoccur after stopping to get fuel, this time it would not start just a clicking noise, everything else working and all voltages appeared ok, we called our breakdown provider, but the van started while waiting from them to arrive, on returning to the UK it went into Adams Morey under warranty and showing them the recording of the issue, they diagnosed the starter motor (mileage now 3.5k) they changed the starter motor and we had trouble free trips for a few months them the same issue happened, this time it started after a few attempts (same clicking noise), van went back to AM and they replaced the earth strap, picked the van up went to Goodwood, stopped the van to get water, and it wont restart (clicking again) this time 45mins later it started, van went back to AM and they replaced the starter motor…. despite our concerns this is not the root of the issues, and advising who has 2 faulty starte motors in a 2yr period, off we went again no issues on multiple trips, then the issue comes back exactly the same again, AM simply not interested, now out of Fiat warranty (original owner was not offered extended warranty when he purchased) we are at our wits end with the problem and reading forums i do not believe we are alone, but i would like to get the issue resolved once and for all, any help or pointers would be appreciated, as we are losing confidence in turning the engine off on long trips (Stop/start working fine) Thanks in advance

 

[348azeus]

I agree that is extremely unlikely to be than unlucky with starter motors .If stop start is working fine then there is nothing wrong with the starter. It uses a different circuit to the normal starter circuit so you could do with getting hold of the motorhome manufactures wiring diagram. They often add addition relays and interrupt the normal circuitry so you may have a difficult to find but relatively simple fix.

 

[AndyFire8]

I agree that is extremely unlikely to be than unlucky with starter motors .If stop start is working fine then there is nothing wrong with the starter. It uses a different circuit to the normal starter circuit so you could do with getting hold of the motorhome manufactures wiring diagram. They often add addition relays and interrupt the normal circuitry so you may have a difficult to find but relatively simple fix.

Thanks i had thought of that as it is almost like there is no supply when the clicking noise is coming from the starter motor, unfortunately i cannot get to the terminals when it has occurred, but the fact that it starts randomly sometimes within a few attempt other times up to an hour or so, has left me baffled and as noted Adams Morey are not interested and it actually occurred once while with them (was in for a Fiat recall on LED indicators) and they said it was the starter motor……

 

[ZaphodB]

Starters are often misdiagnosed

From what you're saying the solenoid in the starter is activating (the clicking), but the contacts aren't closing to provide the mains power to turn the motor (or there's simply no heavy duty 12V at the solenoid connection).

So the contacts are bad, or the 12volts (heavy duty cable) isn't securely connected to the solenoid contacts.

If they actually have indeed replaced the starter motor (for a brand new one), then the solenoid contacts can be ruled out obviously, so the blame needs to be concentrated on the heavy duty cables to and from the starter, alternator and battery.
I'm making a few assumptions as I don't know the exact wiring of your vehicle.

Also the earthing of the starter is just as important, this is normally physically returned from the starter motor casing to the engine, and ultimately through the engine earth strap back to the battery.

 

[AndyFire8]

Starters are often misdiagnosed

From what you're saying the solenoid in the starter is activating (the clicking), but the contacts aren't closing to provide the mains power to turn the motor (or there's simply no heavy duty 12V at the solenoid connection).

So the contacts are bad, or the 12volts (heavy duty cable) isn't securely connected to the solenoid contacts.

If they actually have indeed replaced the starter motor (for a brand new one), then the solenoid contacts can be ruled out obviously, so the blame needs to be concentrated on the heavy duty cables to and from the starter, alternator and battery.
I'm making a few assumptions as I don't know the exact wiring of your vehicle.

Also the earthing of the starter is just as important, this is normally physically returned from the starter motor casing to the engine, and ultimately through the engine earth strap back to the battery. View attachment 468830

Thanks, I’m on my 3rd starter motor, the 1st went in at 2k miles, I sort of wish it happened more often as it would be easier to locate, unfortunately it happens completely randomly, sometimes from cold starting, other times after a journey, I’m leaning more towards a relay as it’s like it’s not getting the switched feed, it’s going in for a service soon, I am going to ask the new garage to take a look, hopefully a fresh pair of eyes on this might spot something

 

[ZaphodB]

Thanks, I’m on my 3rd starter motor, the 1st went in at 2k miles, I sort of wish it happened more often as it would be easier to locate, unfortunately it happens completely randomly, sometimes from cold starting, other times after a journey, I’m leaning more towards a relay as it’s like it’s not getting the switched feed, it’s going in for a service soon, I am going to ask the new garage to take a look, hopefully a fresh pair of eyes on this might spot something

It won't be a relay, the starter gets direct connection to the battery due to how many amps it will pull, the high current contactor (which closes that connection) is in the starter.

Ironically high current cable connections (or the main earth) - when loose - can sometimes make full connection and sometimes not, this is your problem from the what you've said.

 

[RS3100]

I had a similar problem a couple of years ago. It turned out to be a loose connection at the CAL5 fuse terminal stud on the distribution plate at the battery positive terminal. The plain nut securing one end of the fuse had worked loose. I replaced the nut with a nyloc nut and have had no further issues. For some reason known only to Fiat the fuse was secured at one end with a nyloc nut, but only a plain nut at the other end, which was my problem.

 

[Communicator]

From post #1, the vehicle is an automatic. @AndyFire8 you stated that first occurence of the fault was on a December evening. Can you can confrim that this was with a cold engine? This would rule out temperature effects on the starter solenoid.

(The problem has similarities to that which I experienced many years ago on a Talbot Express based MH. It would not restsrt immediately with a hot engine e.g. at filling stations, and campsite receptions.)

@ZaphodB has ruled out the possibility fo a relay. While I am normally sceptical when relays are suspected, in this instance I disagree. On older automatic vehicles at least, a relay was fitted in the engine bay fusebox. This relay provided the interlock betwween the gear selector at "P", and starting the engine.
The relay coil is energised with the key at the start position, ans gear selection at "P". The relay contacts switched 12V directly to the starter solenoid, with the solenoid switching the main starter motor current as normal. I doubt that this has changed significantly ove the years.

As in this case with my problem I used to hear a clunk from the starter solenoid. It is my belief that this was due to the solenoid having insufficient power to complete its travel and close its contacts to energise the motor. On testing I found voltage drops at the ignition switch, and at alarm contacts which had been added into the starter circuit. I added a relay into the starter solenoid circuit and my problem was cured. From subsequent reading I was not alone.

As a first step I suggest replacing the appropriate relay, as it has a more onerous duty than others. The relay has to break the solenoid current which is an inductive load that can cause sparking and deterioration of the relay contacts.

Another possibility is poor connections in the engine bay fusebox, which is uses a set if interlocking folded metal strips instead of conventional wires.

For an appreciation of the fusebox see here.

 

[ZaphodB]

@ZaphodB has ruled out the possibility fo a relay. While I am normally sceptical when relays are suspected, in this instance I disagree. On older automatic vehicles at least, a relay was fitted in the engine bay fusebox. This relay provided the interlock betwween the gear selector at "P", and starting the engine.

What I was saying is there is never a relay on the high current side of the starter feed.

Absolutely there might be relays on the control side of the starter (i.e. the solenoid drive)

I also agree the click indicates the solenoid is getting (some) voltage at least, whether it's enough to fully pull the contactor closed is debateable (unless checked at the starter solenoid terminal)