Technical Ducato Accessories and Starting problem

[EmJayP]

Hi all,

I've had an issue starting my van in the last 24 hours and haven't been able to troubleshoot. Just wondering if there are any thoughts? Here is the breakdown of events:

Starting attempt #1-
- First ignition position- some dash lights came on, headlights came on, no fuel prime sound heard
- Attempted to start engine- would not start but kicked over started motor. Attempted a few times.
- Switched headlights off
- Switched ignition off
- Attempted first ignition position- no lights working

Starting attempt #2 & 3 (the next morning after no luck troubleshooting)-
- Started normally and ran for approx 10 mins

Starting attempt #4 (end of the same day)-
- First ignition position- accessories lit up as normal, headlights on, fuel prime heard
- Switched headlights off
- Started engine normally, ran for 1-2 mins
- Switched headlights on- engine immediately cut out
- Ignition off- faded/flickering battery light and oil light illuminated even when key is out
- First ignition position- only same lights as above plus hand brake light for approx 5 seconds then extinguished, and radio ON button only (it usually completely switches on). No other dash lights, headlights, radio power or fuel pump. Ie accessories aren't working as usual on startup
- Started motor engaged but engine doesn't start

With the key out there's still a faint and flickering battery light and illuminated oil light.

We checked the mega and midi fuses and all appear to be intact so can't work out what it may be. One of the theories is something with the ignition circuit/barrel

Thanks!

 

[jackwhoo]

Check battery connections
Check battery wires , especially the negative wires they can disintegrate under insulation.
Check where negative wire connects to engine/chassis clean and tight.

Battery could be dead or dieing.

 

[jackwhoo]

Give us a clue what year and engine

 

[EmJayP]

Give us a clue what year and engine

2004 Diesel 2.8 (I think it's 2.8. I'll check and update if it's not)

 

[Communicator]

EmJayP,

If your vehicle is 2004 2.8JTD, then it will be similar to mine.

Some of your symptoms, as Jackwhoo has suggested, point towards battery/battery connection problems.

I am puzzled by your partially lit oil & alternator lights. which are both supplied via 10A (red) fuse F37.
On my vehicle F37 is in the LHS cab fuebox, bottom row sixth from left.

If these mystery lights appear again, it could be worth pulling F37 briefly, to prove that the feed is via the ignition switch.
If the above lights stay lit with F37 removed, then consider a faulty alternator diode on the positive side.
A path would then exist from the battery, through the faulty diode, and associated field diode to D+.
From D+ the current could pass via alternator and oil warning lights to earth via the oil pressure switch.


If the above should be a false trail, then as regards battery connections, I have read of a broken positive battery clamp, (that is the one with the M6 bolt partly under the battery fuseboard). You were testing fuses in that area.

 

[EmJayP]

Thanks for your help so far!

I've checked the battery connections etc and it all appears to be fine at the moment.

I haven't had a chance to do those further checks yet, but in the meantime have tried again this morning.

- Same problem with not being able to start initially
- After a couple of tries of key on and off/out, it started normally, and then the engine cut out when I switched the lights on again
- New development- the needles on all of the gauges flicker/jolt on the stops for around 10-20secs even with ignition off and key out

I'll run the checks above to see if that isolates the problem. I came across a thread yesterday mentioning flickering gauge needles so will try and find that again and see what the problem was with that.

 

[Communicator]

EmJayP,

-----------------------------------------------------------------------------------------------
If these mystery lights appear again, it could be worth pulling F37 briefly, to prove that the feed is via the ignition switch.
If the above lights stay lit with F37 removed, then consider a faulty alternator diode on the positive side.
A path would then exist from the battery, through the faulty diode, and associated field diode to D+.
From D+ the current could pass via alternator and oil warning lights to earth via the oil pressure switch.
-----------------------------------------------------------------------------------------------

Old age must be catching up with me!

There is a serious flaw in the logic of the penultimate sentence above. If there was a faulty diode in the alternator, any current passing from the battery would be shorted to earth via the other set of diodes and the alternator stator windings.

 

[jackwhoo]

Gauge needles hitting the high stops is a classic sign of bad battery negative wire or - ve wire between engine and vehicle body.
Admittedly not when key is off but there is always a first time.

Cutting out when switching extra loads(headlights etc) on is also indicator of bad - ve wires , the thick wires from battery or between engine/gearbox and chassis.

If you have jump leads you can try one between battery - ve post and a good clean metal point on engine and a second jump lead between clean metal point on engine and a good clean metal point on body.
Try start see if symptoms changed.

 

[Anthony489]

Hi EmJayP

The fact that the van sometimes starts properly suggests that the main battery and starter high current connections are OK, though still worth checking as you have done. Fuses generally either work OK or blow and don't work at all, but there is always the chance of a corroded contact. Normally taking them out and putting them back a few times is enough to clear this, unless you have had water on them a long time which will show up visually as the metal contacts will no longer be clean and shiny.


I have encountered flickering needles once, when my battery failed and the instruments were only getting about 6 Volts with the ignition on. ECUs will still work at reduced voltage, but I guess 6 Volts was just too low.


Your symptoms suggest to me that there is a fault in the ignition/starter switch which is giving a high resistance connection from the battery through to the electrics. This seems to be happening in some cases even with the key out. The voltage "downstream" of such a poor connection will be highly dependent on the load, so for example if you switch on an additional load like headlights (10 Amps) what little voltage was being achieved will then collapse to near nothing.

With things working normally, some electrical loads are deliberately maintained by the ECU for a period of maybe 10 or 20 seconds after the ignition has been switched off, after which you will hear a click as a relay drops out.

That's about all I can suggest at the moment from my "armchair". The rest is down to you to diagnose, a cheap voltmeter might come in handy to track this one down.

 

[Choady]

G'day all, I am a friend of EmJayP and have unfortunately spent a lot of time over the last week trying to diagnose the problem.

We tried using jumper leads as described by Jackwhoo to see if that helped with the issue - it did not. Also tried starting while charging the battery with a 25 Amp charger - no luck.

I've run some resistance checks between the -ve and various parts of the engine bay which all appear to indicate normal resistance and hence good connections.

It is a very strange problem and it is now an intermittent one. I left the charger on for a day and the next morning all accessory lights came on as normal and it started fine. Turning on lights, running wipers, power windows all at once also posed no problems.

I decided to let it charge for the rest of the day while at work. That night - started no problems - As it did the following morning.

So I was beginning to think the battery was on the way out and all it needed was a good charge but then the issue came back again out of the blue after several days on charge each night. It has not been driven for fear of dying at random.

You can tell as soon as you turn the key to accessories if you are going to have a problem. Either all the lights come on and pump runs etc, or all you get is the park brake, oil and battery light - nothing else. In this case no indicators, headlights, or anything else seems to work. The starter will turn over but there appears to be no ECU to permit the car to run.

Another full check under the bonnet of all mega fuses, relay box in the engine and both internal fuse boxes inside revealed nothing - none had blown.

I then noticed something very strange. The Victron BMV-712 rear battery monitor (which also monitors voltage on starter battery) showed the rear batteries at 12.9V, but the starter at 6V.

I checked the voltage across the starter battery and had 12.8V. The rear battery was 12.9V. I thought the fuse in the cable that went to the BMV from the starter battery may had blown. Checked continuity of the fuse and all good. Just to engineer out the wire, I disconnected it and ran a separate wire - same thing - 6V.

In the rear of the van I recently installed a Victron MPPT solar charger, a Victron DC-DC charger, and a Victron 240V 12 V charger (which runs through shore power) All were working fine. I flicked the resettable fuses one at a time to ensure all but one at a time were isolated and checked individual voltages - all were normal.

The BMV-712 shunt connects to a -ve battery bus and one of those cables terminates to chassis ground. I decided to check resistance and disconnected the chassis ground cable from the -ve battery bus (which connects to the shunt and is in the rear of the vehicle) but accidentally left the multi in volts. Low and behold it was registering 7.0V when I measured voltage over it and the -ve cable that runs directly back to the starter battery.

The 6V was now starting to make sense as the BMV-712 cable that monitors starter battery voltage uses the chassis to ground.

There appears to be only a very small current running through the chassis and I cant even get it to spark.

I am wondering if that is what may be causing the issue as the voltage drop would seem to generate the symptoms we are seeing.

Just in case are were wondering, I disconnected the rear batteries totally, removed all fuses to the components described above to completely isolate the back end, but the 7V through the chassis ground cable was still there. I was able to confirm in the engine bay when I checked voltage across the -ve terminal of the starter battery and a nearby piece of metal ground to chassis that the 7v was in the front of the vehicle too.

Any ideas where it may be coming from ?

I suspect that when I check in the morning, if the accessories come on, the 7V running through the chassis will not be there. The starter is charging tonight again to see if we can make the cycle continue.

 

[Anthony489]

Hi

This wouldn't be the first time that vital information emerges a long way through a string of posts ! It is quite likely that the problems being experienced are connected in some way to the recent comprehensive additions to the standard electrics.

I'm not overly familiar with the Victron monitor, but as with any monitor that needs to measure current it relies in introducing a very low value precision resistance (a shunt) in series with the cable carrying that current. The shunt converts current to a (tiny) DC voltage proportional to the current, which is then measured and displayed by the monitor. The shunt is normally physically close to the high current circuit being monitored, to avoid having to extend thick cables. The voltage monitoring cables only have to take tiny currents, so length is not an issue.


It's vital that the connections to the shunt are 100% solid and capable of taking the full expected current, and that all the maker's instructions are followed. If you are seeing voltage measurements of half what they should be there is clearly something very wrong somewhere. I suggest all the new wiring and devices are double checked before going any further.

 

[Communicator]

Choady, EmJayP,

If I have understood the term "rear battery", and Choady's description correctly you have a rear or service/habitation battery. The negative of this battery is connected to chassis via a shunt. There is no direct connection to the starter battery negative terminal, only via chasis.

On my 2006 2.8JTD the starter battery negative cable connects first via a flag terminal to main earth point C002 located almost under the battery, and in front of the RH engine mounting. The same cable continues under the radiator, to connect to the C003 engine block earth on the clutch housing end of the starter motor mounting stud.

The ECU is earthed at earth point C040, which is situated at the front of the left wing. It follows that power to the ECU and accessories must flow through earth C002, while that for the starter motor does not, with only earth point C003 being in the starter motor main current path.

Given your current problems, I most strongly advise that you disconnect and thoroughly clean the mating surface at earth point C002 under the battery. Reassmble with a smear of thick grease or vaseline.

Access on my vehicle, which does not have aircon, is quite easy.


May I add that connecting a jumper lead between the starter battery negative terminal, and the engine block may not disprove problems with earth point C002.

 

[Anthony489]

Hi again.

Thanks to Communicator's post I now have a clearer idea of your vehicle's setup. Apologies for being wrong about the problem being due to the additions made, as it is now clear that there is a simpler explanation.


On the Post 2006 Ducatos (with which I am more familiar), the earth lead from the battery goes straight to the body only. There is another flexible strap in the engine compartment from another part of the body to engine block and hence starter. If either of these connections are bad the starter will turn slowly or even not at all.

On your earlier vehicle, the earth lead from the battery goes to the body but the same cable continues on to the engine block and starter. With this arrangement, if the connection to the body is bad it WON'T affect the starter, but WILL affect any accessories, lights etc relying on an earth return via the body.

So as Communicator says, take a good hard look at that connection to body. If you want to test it electrically, connect a voltmeter between the starter battery negative (right on the battery) and an independent good earth point on the body. Turn on a big load reliant on a body earth return, e.g. headlights. You may see a reading but it should measure no more than a small fraction of a volt between these two points if the joint is OK. You could tap or wriggle it to make sure.

 

[Communicator]

Choady, EmJayP,

If I have understood the term "rear battery", and Choady's description correctly you have a rear or service/habitation battery. The negative of this battery is connected to chassis via a shunt. There is no direct connection to the starter battery negative terminal, only via chasis.

On my 2006 2.8JTD the starter battery negative cable connects first via a flag terminal to main earth point C002 located almost under the battery, and in front of the RH engine mounting. The same cable continues under the radiator, to connect to the C003 engine block earth on the clutch housing end of the starter motor mounting stud.

The ECU is earthed at earth point C040, which is situated at the front of the left wing. It follows that power to the ECU and accessories must flow through earth C002, while that for the starter motor does not, with only earth point C003 being in the starter motor main current path.

Given your current problems, I most strongly advise that you disconnect and thoroughly clean the mating surface at earth point C002 under the battery. Reassmble with a smear of thick grease or vaseline.

Access on my vehicle, which does not have aircon, is quite easy.


May I add that connecting a jumper lead between the starter battery negative terminal, and the engine block may not disprove problems with earth point C002.

I forgot to add that the designations of the earth points (Cxxx), are those used by eLearn, which is available in the downloads section of this forum.

 

[Choady]

G'day everyone,

Thankyou for your prompt replies. Some updates:

In the morning prior to departing for work - the chassis voltage was still there and the same issues existed with accessories etc and the car would not start.

When I got home from work tonight (incidentally before I had a chance to read these messages), the accessories came on no problems and the car started normally. I had not done a thing since the morning, BUT when I flicked the headlights on, the car immediately died and the cycle repeated itself - no accessories, won't start etc.

I had however let the car idle for about 5 min before I turned the headlights on. During that time I checked voltage between the NEG starter battery terminal and chassis. There was no chassis voltage any more (well, just a fraction of a volt so normal IMO). Can't believe how intermittent this problem is.

So now we are back to square one - there are no accessories and car will not start again.

If I have understood the term "rear battery", and Choady's description correctly you have a rear or service/habitation battery. The negative of this battery is connected to chassis via a shunt. There is no direct connection to the starter battery negative terminal, only via chasis

Now its worth highlighting something here to ensure you fully understand the rear wiring setup. I have a fused +ve and unfused -ve cable connecting the front and rear batteries at their respective terminals. There used to be an old REDARC voltage sensitive relay between the two batteries which I replaced with a Victron 30A DC to DC charger, but the key point is that there is direct connection between the rear -ve battery to the starter negative battery. I do this to try ensure no earthing problems via chassis !!!

During all my trouble shooting, I disconnected both input wires to the DC to DC Charger (+ve and -ve which run from the starter battery via 60 AMP fuse ) and then disconnected the output wires from the DC to DC charger (+ve and neg) which run to the rear battery via another 60A fuse (+ve) and the -ve output goes via the -ve bus and then through the shunt to rear -ve battery terminal).

This effectively isolated the front and rear batteries but at that point I could still check the voltage of the starter battery by measuring between the +ve and -ve input wires near the DC to DC charger at the rear of the vehicle.
I could also measure between the two output wires and this gave me the voltage of the rear battery. Hope this makes sense.

I then disconnected the Solar MPPT Charger and the 240V DC Charger from the positive and negative battery buses in the rear so they are no longer a factor.

The Shunt has one cable direct to -ve of the rear battery (a 900mm long 35mm2, 2AWG). The other end of the shunt connects to the -ve battery bus via a 100mm 2AWG cable.

At this point, there are only three 8AWG cables left connected to the -ve bus. The -ve to the rear fuse block (powers fridge and 12v lights etc), the chassis ground (which is a green cable), and the -ve output wire to the DC to DC charger, which at this point in time is not connected.

When I saw the low voltage of the starter battery on the Victron BMV monitor, I disconnected the chassis earth (green cable) from the -ve bus at the rear of the car, but left it connected to chassis. When I measured voltage between this and the -ve DC to DC charger input cable (ie the cable connected directly to the starter -ve terminal), that is when I saw the chassis voltage for the first time.

Tonight after the car died when I put the headlights on, I disconnected the +ve and -ve cables that are attached to the rear battery. I could still see the chassis voltage between the green chassis cable and the starter -ve.

I then went in the engine bay and disconnected the +ve and neg cables that run to the rear of the car from the starter battery.

I did this to totally isolate the all my wiring and sure enough, when I checked voltage between the -ve terminal of the starter battery and several points in the engine bay - I could still see the same chassis voltage.

So at least now I know it is definitely not my wiring !

I am very interested in trying out cleaning the earthing points you highlighted tonight. It sounds very promising.

Thanks again for your help on this. Great forum.

 

[Choady]

G'day all,

Thought I would give you an update. This morning I pulled the earth point at C002. The connection on the chassis was nice shiny metal, as was where the threaded nut screwed down onto the clamp.

There with no evidence of corrosion or anything else that would affect the connection. I gave both a light file (including the underside of the nut that clamps it on) and then refitted and tightened.

To my surprise, the chassis voltage was now gone. When you turn the key the accessories came on, car started normally. I was stoked, thinking that it must have just been the earth connection so I tried driving out of the driveway, but it died before I got more than a few metres.

The car started, then died two more times - then back to square one. No more accessory lights and the chassis voltage was back. I used my 4WG to winch the Fiat from the middle of the road to the kerb.

Am totally lost as to any explanation. There is continuity between starter -ve terminal and the C002 connection point and other areas of the engine bay.

Fiat has now been towed to the auto electrician.

 

[Anthony489]

Hi

It's difficult without seeing this, but my understanding is that there is a continuous cable from battery to engine block with effectively a "side branch" to the body at C002. You have thoroughly checked the connection between the lug and the body, but I am wondering about the connection between the cable and the lug. This is presumably crimped, and it is possible for corrosion to occur inside the lug even though it feels mechanically tight.

You may be better off adding a new dedicated cable/strap between starter battery negative and chassis, so as to bypass the C002 connection. Even if you only do this temporarily, with a single jump lead for example, it would prove if C002 is the problem.

Remember that these connections must be no more than a tiny fraction of an ohm, and testing continuity with an ordinary meter will not reliably measure the difference between say 0.5 ohm (bad) and 0.01 ohm (good).

 

[Communicator]

Anthony489,


Photo of Ducato x244 chassis earth C002 attached. Not a masterpiece, but visible. Do not be confused by shadow of negative cable. For orientation, part of the RHS engine mounting is visible in the lower RH corner of the picture.

 

[Anthony489]

Hi

Thanks to Communicator for the picture

Hard to tell, but it's possible the lug isn't even crimped by design but merely wrapped round, in which case I'd be even more suspicious of its contact to the cable.

 

[Communicator]

Nothing is as simple as it seems. In a previous reading the eLearn diagram E5010 in the relation to the earths, I assumed that it would be a logical picture of the state of affairs, and that the earth connection closest to the battery would be shown in a similar relative position on the diagram.

Alas, further delving reveals that I assumed incorrectly. Hence the chassis earth is C003, and the earth connection at the starter motor is C002.

Looking at outlines of C003 (chassis earth) on eLearn, it shows somthing quite different to that in my photo above. On eLearn the lug at C003 is shown with the crimping section offset so that double "C" style of crimping, as used at the battery, could be used.

As touched upon by Anthony489, the crimp lug on my vehicle appears only to be tightly sqeezed round the cable, without any indentation. I suspect that the lug, in common with others, is made from tin plated steel.