Transit alternator issues

[Mark22]

Hoping somebody can help....we had a 12 plate transit 2.2tdci transit brought into us, the customer had broken down and another garage fitted an alternator (lucas), on his journey back the engine malfunction light came on along with the esp, we had a look at this and the alternator was only putting out 12.2v at idle, we removed that alternator and replaced with Bosch. The van now intermittently charges at over 14v then drops to 12.8v and this is when the malfunction lights appear, is this a case of only ford genuine alternators are compatible for thesd vehicles?

[iantt]

I would check the wiring for corrosion at the connector or chaffing somewhere  to the alternator ( the field wires ) 

Also check at the pcm end for corrosion.the  make of alternator will be irrelevant. 

[Mark22]

Forgot to add aswell that it isnt the smart charge system its only single wire plug, when i disconnect the alternator at idle it shoots from 12.4 to 13.7??

[Tdci-Peter]

1 hour ago, Mark22 said:

it isnt the smart charge system its only single wire plug,

The Mk3 Focus smart charge system only uses a single wire plug. It is a digital bus (LIN) system. A 2012 Transit would likely be the same. In which case it will need the correct LIN bus smart charge alternator.

[Mark22]

By disconnecting the plug the voltage jumps up, this is the ecu putting it in default and regulating the voltage, would you be looking more towards the wire or alternator?

[Tdci-Peter]

33 minutes ago, Mark22 said:

By disconnecting the plug the voltage jumps up, this is the ecu putting it in default and regulating the voltage, would you be looking more towards the wire or alternator?

As the alternator seems to be responding to the commands from the ECU via the wire, it suggests the alternator is the right basic type. It is possible there are minor variants (eg software changes) that would give wrong results if the wrong variant is fitted.

Or it could be the alternator has been ok all along, but some other sensor is playing up and making the ECU set the wrong voltages. Does the van have a BMS (battery sensor) mounted on the battery terminal? These can go faulty and give wrong current or voltage readings to the ECU. Or even the ECU memory could be corrupted or adjusted itself badly. An ECU reset or adaptions reset might be possible.

If the MIL or similar warning comes on, there should be an error code stored. Sometimes (but not always, unfortunately!) this can give a helpful clue as to the real cause. A lot of OBD reader systems can not read all the codes stored in more modern vehicles. If there is no access to Ford IDS, then Forscan seems to be the next best system.

[Mark22]

Am i right in saying with it being smart charge there usually putting out 14.5-15v? With me disconnecting it and it only going to 13.5v surely the alternator isnt reacting enough?

[Tdci-Peter]

4 minutes ago, Mark22 said:

Am i right in saying with it being smart charge there usually putting out 14.5-15v? With me disconnecting it and it only going to 13.5v surely the alternator isnt reacting enough?

There is a lot of talk about Ford Smart Charge on the 'net, but a lot of it is wrong or misleading. The reason I say that is that it is handled in the ECUs, and these are not usually made by, or directly programmed by, Ford. They usually come as part of the fuel, injection or ignition package from the likes of Bosch, VDO or Delphi. I guess Ford has an overall spec. for the charging algorithms, but they will be interpreted and implemented (or not!) by others.

So it is largely guesswork as to the details of voltages, and the way it responds to load and temperature. But there are underlying facts, like the voltage for full charge of any lead-acid battery, including Calcium, Silver, EFB and other variants, will be 14 to 14.8v, usually about 14.4v. The float voltage for charge maintenance will be about 13.6v, and about 12.6v for standby. So 15v or more, unless briefly in very cold conditions maybe, is wrong, And below 12.6v will be actively discharging the battery. If it does not get to well over 14v at sometime in a drive cycle, then it will not get full charge.

With the wire disconnected, usually the alternator will revert to internal control like an older unit. The exact voltages will vary depending on manufacturer. But will still be in the lead-acid limits above. 13.5 on idle may be normal, but it should rise to over 14v with a few rpm.

You said; " The van now intermittently charges at over 14v then drops to 12.8v and this is when the malfunction lights appear, " in the 1st post. Those voltages sound fairly reasonable, though the over 14v bit should happen reliably in a drive cycle, ideally soon after starting. The bit that is really wrong is the light coming on, the cause of that really needs to be found. Monitoring voltages may give a clue, but DTCs might help more.

I am assuming it does not have stop/start or regenerative charging, if it does then there there are added complications like aiming for 80% charge instead of 100% charge. Diagnosing that system is almost impossible, it seems to me!

[Mark22]

The engine malfunction light is 100% being brought on by the voltage drop when driving. With the alternator connected when driving it charges over 14v, looking at the tester as soon as it drops to 12.5v the malfunction light instantly comes on.

[Ryg]

On 2/3/2019 at 7:17 PM, Mark22 said:

Did you ever find out what this was? 

 

[Ryg]

Did you ever find out what this was? Having same problem with a transit 

[Dave Willy]

Ok, I've purchased a transit connect 2010 1.8 trend. Refrigerated van was running and starting perfectly well then the fan belt snapped. I had it replaced but the battery light was on. The mechanic said he'd tried several different belt but can't get it off. Slowly but surely the battery light has turned red from amber.

I'm just wondering wether to call the company who fitted the refrigerated unit to the van and see if this can help. As it would have had to be upgraded because of the fridge unit I'm no mechanic by far. Don't know wether it's the battery itself, wrong belt or starter motor. Any help or advice would be greatly appreciated.

 

 

[Tdci-Peter]

9 hours ago, Dave Willy said:

Don't know wether it's the battery itself, wrong belt or starter motor.

It can not be the belt. If that was slipping more then just the smallest bit, there would be smoke and a smell of burning rubber. A lot of energy passes through that belt. A wrong belt can not make the alternator turn slower without slip, and consequent friction heating. It will not be the starter motor. If the van starts ok, it is not likely to be the battery. So that leaves the alternator, the wiring and the electronic control units. I would start by checking the main earth & power wiring connections, then having the alternator (and its pulley) fully tested. As you say, it should be an upgraded unit to cope with the refrigeration plant.

[Jaye Green]

Hi iv got a 14 plate custom showing battery light iv changed altenator and new battery still doing it any ideas 😓

[Tdci-Peter]

2 hours ago, Jaye Green said:

iv got a 14 plate custom showing battery light

You need to check for DTCs using a good diagnostic system. Many generic systems will not get these charging codes. Forscan should be able to. If that fails then Ford dealer IDS may be the only other way to read them.

[BenGibbs1978]

Hi 

I have a fwd 2012 2.2 transit

my alternator is charging at 12.2v no higher on idle or higher revs. until I unplug the single wire off of the back of the alternator then shoots up to 13.5v.  (This is normal) I have a new battery that holds charge. 
any ideas please this is my work van and I’m charging the battery every night so I can get to work 

 

[unofix]

Earth straps between engine and chassis are:

Missing 

Broken 

High Resistance 

Use a digital multimeter and measure the resistance between the metal case of the Alternator and the negative battery terminal it should be less than 0.5 ohms.