Ford transit mk8 2015 2.2 not charging

[Rhino246]

Morning all,

I have a transit MWB 2015 2.2

After a mile or so the battery light comes on, I’ve tested the battery on idle and it’s only 11.8v so not charging. I believe it’s a smart charging system, I have a twin battery set up from standard. 

Can anyone help with this fault? Is there any testing procedure or wiring diagrams I can see to help me diagnose this issue

Thank you in advance 

[unofix]

Seems like a simple case of the alternator has failed.

If when the engine is running at a fast idle the voltage at the battery terminals is less than 12 volt then there is no output from the alternator.

[Rhino246]

Hi unofix, 

 

I would normally agree however there should be 12v at the + lead to the alternator but I have no supply, which leaves me thinking something else is up 

[unofix]

If you're saying that with engine off and testing the large heavy cable that runs between the battery and the alternator that there is no voltage at the alternator end then I'd agree, and say you have an open-circuit.

There is a very heavy duty fuse in the alternator feed near the main battery. I know you have two, but main fuse will be near/next to the standard battery that all Transits have. If the alternator has gone short-circuit (faulty rectifier pack) then an extremely large current can flow which is enough the blow the charging circuit fuse. 

[Rhino246]

That’s correct tested for voltage at the alternator without it running and I get 0 volts 

 

i have checked every fuse I can find, there’s a 460 or 470 amp (can’t remember which) fuse by the battery which says it feeds the starter and alternator but that’s all ok, I can’t find anything else in the book or online that fuses the alternator. 
 

I've checked all the engine earths, and the van starts and drives fine just doesn’t charge. 
 

do you know of anywhere I can get a wiring diagram from? 
 

I’m at the stage I can’t do anything else without a wiring diagram really

 

[unofix]

34 minutes ago, Rhino246 said:

I’m at the stage I can’t do anything else without a wiring diagram really

I will upload the Ford workshop wiring schematic for the Transit 2014 onwards, to my Google drive.

https://drive.google.com/file/d/1iLLte8bh_pPTpjs_T8Szn-PpcQ9TXQPT/view?usp=sharing

[unofix]

Main Charging Circuit.

[Rhino246]

That’s great thank you,

 

Do you know how many wires go onto the starter motor? I only ask because this fault has only starter since that was replaced and I see the alternator gets its supply from the starter and wonder if a wire has been left off 

 

[unofix]

Looking at the schematic the main power cable from the battery goes to the large terminal on the solenoid. I expect that the outer diameter of this cable to be around 10mm and it will be red. Also off the exact same terminal of the solenoid will be another large cable (also red) but slightly smaller in diameter possible about 6mm. This will go from the solenoid to the main output of the alternator.

The possible error that has been made when replacing the Starter motor/solenoid is that the solenoid has two large terminals on the back of it. One is the power input, and the other is the output from the solenoid to the actual starter motor. IF, the cable from the alternator has been connected to the solenoid output terminal instead of being connected to the same terminal as the battery lead then you get the fault that you have.

This of course would mean that the output from the alternator has been directly to the starter motor input, so I can only guess at what damage to either the starter or the alternator has been caused. You may be lucky and nothing will have been damaged.

Please remember these cables can carry hundreds of amps. DISCONNECT the negative lead from the battery before investigating possible faults with the wiring of the solenoid.

[Scott350]

Hi

Get Forscan you can test pretty much every part of the van inc independent modules. My post is new under mk8 problems. Screenshot Useing Forscan showing the alternator communication error .Mine throws the battery light on after a short time but charges steady at 13.64v , batteries never go flat and it always starts. Forscan is cheap and really good and I just ask the folk who really know it when I get a bit out my depth. Saving me a fortune considering how bad these mk8 are. 

[unofix]

1 hour ago, Scott350 said:

on after a short time but charges steady at 13.64v ,

That is the default charging voltage for when the alternator smart charge circuit has a fault.

Check the small connector on the alternator (little plug with 2 or 3 wires) and you most likely find a poor connection and or damaged wire near the plug.

[Scott350]

Sorry to the original poster for coming on your thread. 
It’s a single wire on the plug. I’ve got most the engine parts out now trying to find another fault lol. I’ll check the loom as you suggested 👍

[Scott350]

Whilst investigating another issue and moving said wiring to back of alternator the plug snapped off at the wire. It seemed solid. Might not fix my issue but  just shows you the wiring is made of some low grade parts. 

[unofix]

15 minutes ago, Scott350 said:

wiring to back of alternator the plug snapped off at the wire.

mmmmm........................  whats that old saying ??? 🤣

[Scott350]

Box off matches and some petrol ? 😂

[ghastly banjo]

Hi, I have mk8 2014 was doing same, BUT still charging,, check fuses under steering column for a fix.