X250 Engine earth fault

[aandncaravan]

andytw - 2016-12-24 3:29 PM

 

I also had different but classic symptoms of faulty earth. My problem was --> start engine, leave at tickover, then revs would increase, then battery light would come on. However if engine rev' after starting all was well.

I fitted new strap and did lots of testing 'knowing' it was an earth fault. Turned out to be the alternator.

 

Andy, Some Alternators can be a bit 'lazy' to trigger and a few more 'revs' after starting will allow the Alternator to build up enough voltage to then go into 'charge mode'.

This is especially true if a big load is placed on the Alternator, like a poor Habitation battery or a large battery bank.

 

Alternators in this 'lazy' state can go on for thousands of miles, without issue, it is not necessarily a sign of impending failure.

 

Always a good idea to give a few extra revs, no more than a fast idle, for a second or two after starting a Motorhome engine as it ensures the Power distribution/Charger kicks in straight away. Especially important if the habitation battery bank is quite big or discharged.

 

 

We would suggest that the Earth strap on a Motorhome is replaced as a matter of course after around 4 - 5 years because of the impact it can have on charging the habitation batteries when running off the Alternator. A poor Earth strap has the potential to more than half the charge rate to the Habitation battery.

 

 

We covered on another thread, how we cut open a number of Earth straps we removed and how we found inside a White and Green corroded mess. We think down to the fact that the Fiat Earth strap is a Copper cable braid, sometimes tinned and sometimes not, with Steel eyelets crimped on the ends resulting in dissimilar metal corrosion.

If Water/Salt gets into the 'braid' there is a very high chance the strap will fail at some point.

 

That is why cleaning them up rarely works as the issue is inside the crimped on eyelet, not between the eyelet and the Gearbox/body.

 

We think changing to an all Copper strap will eradicate the corrosion problem.

 

 

Microblackcat, When you jump started the engine did you connect the negative clamp onto the engine itself, the body or the battery?

Experimenting with a 12v battery and connecting the negative clamp to different places on the vehicle when you start should give a clue as to where the issue is?

 

I would suggest you may have an issue between the battery negative and the vehicle body?

Try running a new strap from the battery negative down to the body, ideally to where the Gearbox strap meets the body.

 

 

 

 

 

[andytw]

aandn.....all fair comments but there was no load on the alternator from anything but the engine and vehicle battery. Leisure battery condition not of concern, as D+ was not bringing in the split charge relay. I checked.

You are probably correct the old alternator was lazy. So lazy in fact that it often didn't get up.

 

 

[euroserv]

I have replied to Microblackcat by pm but thought i should add here that there is normally a warning provided by the ECU that the alternator output is too low. The normal 850 ish rpm at idle will increase to 1200 to 1400 and the battery charge lamp will illuminate. This is also sometimes a sign of a particularly bad earth, so that needs to be checked first before the difficult and expensive swapping of alternators but as a rule; if you are getting a few random warning codes coming up, it's an earth fault. If it is one consistent warning code; it's normally a wiring fault or actual device fault.

 

N

[BrianBW]

I made this suggestion a couple of years ago on this forum. I was ridiculed, as it was not in the handbook one said. For those who don't have a Halfords close by, do as I have done. Get some heavy antenna cable, join the inner and outer and there's your repair.

Household antenna cable is no good.

[Arthur Brown]

Hi

For emergencies carry a jump lead and in the event of a problem clamp it from body to engine. It used to be battery to engine but they hide the batteries these days. You have all the symptoms above so it your conclusion is a bad earth then keep trying the jump lead until you get a fix. That gets you home, now go and replace the earth which you have confirmed as suspect.

Art

[Microblackcat]

This Forum is fantastic .. I just wanted to thank all the participants for their constructive inputs. Lots of food for thought and further investigations in the new year.

Hope everyone has hassle-free travels in 2017 !

Thank you again.

[aandncaravan]

An X250 Earth issue of a slightly different nature?

If you fit extra batteries, the extra load on the Alternator can be significant.

An Alternator that can output 180amps is going to need an absolutely perfect Earth path back from the Starter Battery/Habitation batteries to it's mounting on the engine.

 

Don't assume that just because the Gearbox has a good Earth point that there won't be corrosion where the Alternator mounts on the engine or at any other point.

 

If you know you are going to be drawing big amps from the Alternator, consider fitting a separate Earth strap from the Starter battery earth terminal to the Chassis, then on to the Alternator body itself.

 

 

Before we went on holiday we had a Motorhome with 4 habitation batteries that were not being charged properly. Voltage at the Hab battery bank when the Alternator was running was only 13.2v not the Alternators 14.4v.

Additionally there were badly burnt connectors on the EBL 99 Fridge Earth points.

The Fridge earth return had clearly been passing a lot of current, yet the Fridge Live connections were perfect so the current hadn't come from there. The damage was too bad to perform a full post mortem, but it seemed as though something else had been using the Fridge Earth path.

The fridge had very good Earth to chassis connectivity because of the 240v Earth bonding, so maybe the Engine/chassis earth had a weakness somewhere and current was finding it's way back to the vehicle chassis via the Fridge Earth?.

We replaced the Body to gearbox Earth strap and gave the Alternator it's own Earth.

 

When we finished the above Motorhome, the voltage drop difference between the Alternator voltage at the Starter battery and Habitation battery was just 0.1v different, one of the best we have ever seen.

 

The current passing through the Fridge Earth connections on the newly repaired EBL 99 was normal, so definitely not burnt by the Fridge drawing too much current.

 

 

We think that the slow, gradual uprating of the Alternator over several years has led to it's Earth current path requirement not being fully considered? A 180 amp Alternator is in the same 'Current league' as a 1970's Ford Cortina's Starter Motor. Back in those days it was realised that for long term reliability an Earth strap very close to where the Starter motor mounted on the Engine/Gearbox was a good idea.

We think it should now be the same for the high power Alternators, which can be running for hours not just the seconds it takes to start a modern engine.

Did I read somewhere that a 200amp Alternator was going to be a 2017 option?

 

At the bottom of our web page 'How does a Charger Work', http://www.aandncaravanservices.co.uk/how-does-a-charger-work.php

is a rough section on how to test the effectiveness of Earth points on a Motorhome.

 

 

 

 

[Robbo]

Thanks Allan for your post of today - very interesting.

 

It prompted me to do a quick health check. With engine running, I measured 13.7v at both starter and leisure batteries (Fiat X250). Leisure batteries are 2 x Varta LFD90.

 

I had suspected for some time that something was not working properly in the battery department. My previous van, a Hymer (Fiat X244) was excellent at retaining leisure battery power (2 x 80Ah gel).

 

So, it's a new chassis/gearbox battery strap (Halfords solid type) and if that doesn't improve things, an extension strap to the alternator.

 

Many thanks for the heads-up :-D

[aandncaravan]

Robbo, please can I ask you to consider something, the results of which might be useful to others?

 

As you have a Voltmeter and seem quite handy, please will you consider running the Earth 'tests' mentioned in the link above at the bottom of the 'How does a Charger work' page before you do any remedial work?

The 'testing' is basically just a process of using a 'Black' jump lead to simulate the fitting of 'new' Earth strap at various points.

 

It might be an interesting exercise for some to see what voltages you record and how you do it? For example did the 'test process' we publish actually identify where the issue was before you started and can you improve the test?

 

 

Can we also suggest that you keep an eye on the two Varta batteries, as your comment they didn't seem to last so long suggests they have not been getting fully charged?

Although this might be expected with the voltage variance from normal, the batteries may have spent a little time in a semi discharged state?

 

I am not a believer in the battery desulphation programs some charges claim to have, as Sulphation is unlikely to be the prime cause of a MH batteries decline. However with you having such new batteries and a verified 'undercharge' situation, it might be an idea to try it out on your Vartas?

 

 

 

 

 

 

 

 

[Microblackcat]

Thanks for all the suggestions ..

 

I feel I need to obtain a couple of earth cables .. one from battery terminal to chassis, and one from chassis to alternator ?

But I'm not very savvy getting around the X250 engine. Can these be replaced from 'above' or is it necessary to remove the under-trays and get at them from below the vehicle ?

Also, can anyone advise what length would be suitable for these two cables as I want to order them on eBay .. don't want to order too short or unnecessarily too long !

Finally, searching eBay I find cable from 16mm2 to 70mm2 section area. I have starter + 2 leisure batteries in my Knaus. I assume bigger the better, but can 70mm2 be 'threaded' around the engine bay etc ?

 

Thanks again.

[Robbo]

aandncaravan - 2017-02-25 3:02 PM

 

Robbo, please can I ask you to consider something, the results of which might be useful to others?

 

As you have a Voltmeter and seem quite handy, please will you consider running the Earth 'tests' mentioned in the link above at the bottom of the 'How does a Charger work' page before you do any remedial work?

The 'testing' is basically just a process of using a 'Black' jump lead to simulate the fitting of 'new' Earth strap at various points.

 

It might be an interesting exercise for some to see what voltages you record and how you do it? For example did the 'test process' we publish actually identify where the issue was before you started and can you improve the test?

 

 

Can we also suggest that you keep an eye on the two Varta batteries, as your comment they didn't seem to last so long suggests they have not been getting fully charged?

Although this might be expected with the voltage variance from normal, the batteries may have spent a little time in a semi discharged state?

 

I am not a believer in the battery desulphation programs some charges claim to have, as Sulphation is unlikely to be the prime cause of a MH batteries decline. However with you having such new batteries and a verified 'undercharge' situation, it might be an idea to try it out on your Vartas?

 

No problem Allan, I'll run the test tomorrow as outlined in your link and report back.

 

My 2 Varta batteries (1 year old) have performed much better than my previous AGM's (no surprise there then !!!). I've always recharged the Varta's when they get down to 12.6v (as shown on my NASA BM-1 meter) although there has been the odd occasion when they've got down to 12.2v when on tour.

 

From what you say, it definitely looks like I have an earth problem - watch this space 8-)

[Robbo]

Microblackcat - 2017-02-25 6:59 PM

 

Thanks for all the suggestions ..

 

I feel I need to obtain a couple of earth cables .. one from battery terminal to chassis, and one from chassis to alternator ?

But I'm not very savvy getting around the X250 engine. Can these be replaced from 'above' or is it necessary to remove the under-trays and get at them from below the vehicle ?

Also, can anyone advise what length would be suitable for these two cables as I want to order them on eBay .. don't want to order too short or unnecessarily too long !

Finally, searching eBay I find cable from 16mm2 to 70mm2 section area. I have starter + 2 leisure batteries in my Knaus. I assume bigger the better, but can 70mm2 be 'threaded' around the engine bay etc ?

 

Thanks again.

 

From chassis to engine you need a 18" (45cm) cable from Halfords, £5. I haven't fitted mine yet but understand you need to remove the air filter and fit from the engine compartment.

 

Don't know what length you need from engine to alternator but might be able to suggest something tomorrow after further investigation.

[MrWoo]

Many thanks Nick,

 

Your technical know how is greatly appreciated.

[Microblackcat]

Many thanks Robbo .. be interesting to hear how you got on !

[Robbo]

Apologies Allan but testing aborted today. Lack of suitable length of cable to run from engine to starter battery (located in cab).

 

However, I did join 2 jump leads together (not ideal) between engine block and negative post of starter battery and registered 14.0v. Switched on some load (12v fridge) and it dropped to 13.5v.

 

Will try again tomorrow as I've just found some thick cable lurking at the back of the garage.

 

[aandncaravan]

Robbo, don't apologise. You have already highlighted that my extra long Trade Jump Leads make a difference to the way most people will tackle the 'test'. So I have just updated the web page accordingly. Thank you.

 

For this test, the cable thickness is not crucial as the current passed during the exercise should be low and the voltage drop of the cable less significant than a poor connection. Cable as thin as 4.5mm should be enough to highlight where the issues are on your vehicle?

 

 

 

 

 

[Robbo]

Allan, finally did the test as described on your website. Eventually found the alternator, hidden at the back of the engine (Fiat x250) and quite difficult to get to. Had to put the van on levelling ramps to access this area. Cleaned up the protruding lug on the alternator body to shiny and bright.

 

Test load on starter battery (SB) – 170w fridge and 2 x 55w headlights (280w or about 23 amps)

Test load on leisure batteries (LB) – internal lighting, 4 amps (measured on NASA BM-1 meter).

 

Initial testing revealed a suspect earth connection between starter battery neg post and chassis earth. Removed cable, cleaned all points of contact, applied Vaseline and replaced. Test results improved especially on no-load. Also, the engine seemed more eager to start !!!

 

Testing carried out:

Alternator to VM (volt meter) to +’ve post on SB, 13.6v at SB (with load), 14.0v at SB (no load).

Alternator to neg post on SB (with load). 13.5v at SB and 13.2v at LB.

Alternator to neg post on SB (no load). 14.0v at SB and 14.0v at LB.

Prior to the testing the SB indicated 12.5v and LB 12.6v (without engine running).

 

I also did testing with the test lead connected to the engine block and the results were similar to those recorded above (ie. test lead connected to alternator). This would indicate that the earth bonding of the alternator is satisfactory.

 

Subsequent testing without test lead gave similar results to above, except the readings were about 0.1v higher for both the no-load and load condition. Perhaps this was due to volt loss in the test lead?

 

The one thing that puzzles me is, the CBE 12v distribution box doesn’t seem to go to a chassis earth. The LB pos lead goes to +B2 (terminal 31) and the LB neg lead goes to –B2 (terminal 33). There doesn’t seem to be a direct connection to a chassis earth. Perhaps this is to avoid starter motor current affecting the habitation electrical circuit.

 

I don’t think there should be a reduction in voltage when load is applied. The search goes on but in the meantime I'll replace the engine earth strap.

 

 

 

 

 

[Alanb]

Robbo said above

 

"The one thing that puzzles me is, the CBE 12v distribution box doesn’t seem to go to a chassis earth. The LB pos lead goes to +B2 (terminal 31) and the LB neg lead goes to –B2 (terminal 33). There doesn’t seem to be a direct connection to a chassis earth. Perhaps this is to avoid starter motor current affecting the habitation electrical circuit."

 

Hi Robbo,

 

That would puzzle anybody, as it will not work. There must be a return path for the leisure battery (B2) charging current. The CBE 12V distribution board in my IH PVC originally had a 6mm connection from the B2 -ve terminal to the -ve terminal of starting battery (B1). I supplemented this by making a common earth point with an M8 brass stud. This stud is locked into a cleaned spare tapped hole in the turntable seat base. The seat base is of course securely bolted to the vehicle.

 

I have wondered what would happen to the 6mm cable, if the normal engine earthing deteriorated, but at least in my early 2006 (X244 Ducato) the starting battery negative connects to the engine block at the starter motor, and then to the chassis,

 

My apologies to Nick for hi-jacking his thread a little.

 

Alan

 

 

[Robbo]

Alanb - 2017-03-07 9:37 PM

 

Robbo said above

 

"The one thing that puzzles me is, the CBE 12v distribution box doesn’t seem to go to a chassis earth. The LB pos lead goes to +B2 (terminal 31) and the LB neg lead goes to –B2 (terminal 33). There doesn’t seem to be a direct connection to a chassis earth. Perhaps this is to avoid starter motor current affecting the habitation electrical circuit."

 

Hi Robbo,

 

That would puzzle anybody, as it will not work. There must be a return path for the leisure battery (B2) charging current. The CBE 12V distribution board in my IH PVC originally had a 6mm connection from the B2 -ve terminal to the -ve terminal of starting battery (B1). I supplemented this by making a common earth point with an M8 brass stud. This stud is locked into a cleaned spare tapped hole in the turntable seat base. The seat base is of course securely bolted to the vehicle.

 

I have wondered what would happen to the 6mm cable, if the normal engine earthing deteriorated, but at least in my early 2006 (X244 Ducato) the starting battery negative connects to the engine block at the starter motor, and then to the chassis,

 

My apologies to Nick for hi-jacking his thread a little.

 

Alan

 

 

Many thanks Alanb for your comments.

 

My CBE manual states that Terminal 33 (-B2) is to connect to the negative pole of the leisure battery OR to the chassis of the vehicle. There are 2 other smaller diameter wires connected to Terminal 33 but these are probably for low wattage lighting etc.

 

What you say, and the modifications you have made, makes sense. I shall rig up a test lead to chassis and hopefully that should improve things no end. I will take the precaution of first starting the engine and then connecting the test lead to earth/chassis.

 

[aandncaravan]

Robbo, Most Motorhome 12v systems don't have a direct chassis connection because they have their own cabled negative path battery to battery. In most instances, a Live and Negative cable will route out from the Power Distribution/Controller to each device, not just a Live with a chassis Earth

.

So when you consider just the 12v supply in isolation, i.e. not the Alternator charge function, a connection to the Chassis isn't required. However, when you bring Alternator charging into the equation the Alternators negative is through the Alternator body, through the engine and then via Earth straps to the battery.

Depending on the vehicle, one or more Earth straps may become the return path for the Alternator current.

 

 

The fact you are getting only 14.0v, not 14.4v does suggest an issue somewhere? As does the fairly big drop under load.

Both will have a detrimental effect on the charge rate of the habitation battery.

 

I think if you did as AlanB has done and ran a 6mm Earth lead from your power units '12v negative' direct to the Engine/Alternator rather than AlanB's chassis connection, it should ensure you get a good return.

It is ok going to the Chassis, so long as the Chassis to Alternator route is already perfect, but we know these can be suspect.

 

A poor Earth is maybe not the primary issue in your case, maybe poor connection on the Live feed, but it certainly won't do any harm.

 

 

 

 

 

 

 

 

 

[Mick Bajcar]

In view of what Andy said as his last comment :-

 

A poor Earth is maybe not the primary issue in your case, maybe poor connection on the Live feed, but it certainly won't do any harm.

 

I had what was essentially a similar problem, the leisure battery was not charging and the problem which others here, including Andy, helped me to resolve was just that, a high resistance on the positive side,

 

http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Chausson-Welcome-76-fridge-running-off-battery-Help/43400/#M504619

 

Mick Bajcar

[Alanb]

aandacaravan said

 

"I think if you did as AlanB has done and ran a 6mm Earth lead from your power units '12v negative' direct to the Engine/Alternator rather than AlanB's chassis connection, it should ensure you get a good return."

 

May I correct a small error in the above statement,

 

I stated that the 6mm return cable to the vehicle battery negative was existiing. The connection to the vehicle chassis came about somewhat by accident, when I was upgrading the leisure battery cables to 16mm, and needed a common negative point near to the leisure battteries. I did not see the need to insulate it from the chassis, other than to cover for the possibility of the starting battery to engine connection becoming faulty, to the extent that the starter return current would try to flow down the 6mm negative cable. It could get rather hot!

 

If as the thread title suggests, there may be possibility of problems with the starting battery earth connection, it may be a good idea to only have one route to the vehicle chassis. I agree with Allan that the most logical connection point for this is at the alternator.

[Mike88]

Do earth problems still exist on the latest Fiat Ducatos?

[aandncaravan]

Mike88 - 2017-03-10 11:47 AM

 

Do earth problems still exist on the latest Fiat Ducatos?

 

Yes because the issue is the design/materials of Earth straps now in common use.

They are generally (as in all vehicles) Copper cable or Braid with steel eyelets crimped on the end of the cables. Corrosion caused by dissimilar metals in contact with each other becomes a problem inside the Eyelet where it crimps over the Copper cable.

If you cut open one of these Earth lead eyelets after about 5 years of use they are a mess of White and Green powdered corrosion. Yet look fine from the outside.

That is why cleaning the contact points on the Gearbox never resolves an issue, which it might have done years ago when the Eyelets were Copper, matching the cable. Back then the galvanic corrosion was usually between the Copper Eyelet, the Aluminium Gearbox casing and the Steel Bolt.

 

This corrosion is made worse on the Fiats because the Earth strap is low down in the engine bay so the strap is in the road water/salt spray.

This is not a Fiat only issue, it applies to most motorhome manufacturers, the Fiat issue is only better known thanks to Nick of Eurserve highlighting it for us.

 

Suggest that you consider replacing your Earth leads at the next service if they are more than 4 years old?

 

See here for a supplier of quality Copper/Copper leads : http://earthbraids.com/copper-flexible-connectors/copper-braided-flexible/#

 

 

 

We worked on Tom Clayton's Fiat (2005 pre X250) this morning which came to us with a habitation battery Alternator charging issue.

There had been a history of charging from Alternator problems since purchase many years ago. Even resulting in a trip to Schaudt in Germany to try and resolve it. In 2011 they had a bigger Alternator fitted with 110amp output.

 

We quickly got the Alternator charging at 12amps but the Alternator voltage at the Habitation battery was a poor 13.7v. Starter battery was 13.9v.

This would provide almost 'adequate' Alternator charging, just slower than ideal, so I continued investigation.

 

If I put the negative of the of the volt meter directly on the engine block it recorded a very strong 14.51v from the Alternator, but at the chassis or on the Starter battery negative it was the lower 13.9v recorded above. Clearly something restricting the charge from the Engine block to the battery, mostly likely Poor earth straps.

 

Because Tom and his wife are catching the ferry tomorrow for a long trip down to Spain they wanted to get going once they had some charging even though it wasn't perfect.

So we identified two points for Tom to run his own cable which he was going to do when he got to Spain.

 

On this Hymer A class Fiat, engine access wasn't great and the Alternator hard to get to, so I suggested running a cable from the Battery negative to the Engine lifting Eye which had a 10mm bolt into the bracket which wasn't being used.

 

Shame I didn't have longer to play, but Tom is going to let us know the impact of the fitted cable on the charge rate.

 

 

Photos below of Galvanic/dissimilar metal corrosion between Steel and 6mm thick Ally plate, then a typical high failure rate cable followed by an Earth strap with Tinned Copper cable braid and Copper ends.

 

 

[Robbo]

Many thanks AlanB, Allan (AandN) & Mick Bajar for your very useful comments. Certainly, food for thought.

 

Currently, preparing to install supplementary heavy duty earth cable from lifting bolt on engine block to chassis OR negative post of Starter Battery, providing I can find a route through to the cab where Starter battery is located.

 

Similarly, 6mm sq from negative of Leisure battery to chassis OR to negative post of Starter battery if a convenient route can be found.

 

Since the Leisure batteries do receive a charge from the alternator (albeit not very much) there must be some kind of earth return from the negative side of the Leisure batteries, but I haven't found it yet, only a couple of thinnish wires heading towards the rear of the habitation area.

 

As suggested by Allan, I'll double check the integrity of all the live connections.

 

I'll report back on progress asap.