Hi all, bit of background, 14 years ago I had a 2006 1.8 TDCi Focus, a whining sound started one day and the alternator got very hot, I think voltage test showed not charging, drove to auto electric specialist and they diagnosed failed diodes/rectifier, which they repaired for £145 all in (a bargain looking back). I was told this was common fault for the model.

I've had a 2009 1.8 TDCi Focus for several years, the other day I heard what seemed to be the same whining sound  I stopped straight away and alternator seemed pretty hot, considering I hadn't driven far and engine wasn't fully hot. The wining goes up and down with the engine speed although you can't really hear once engine goes above ~1500rpm. I didn't have a meter with me to check voltage. Drove home then later started the car, couldn't hear sound, and voltage on battery was around 13.8v so seemed fine. Next day went for short trip and again couldn't hear the sound.

The day before I heard the sound, I'd done a long journey with no issues, and the battery is 2 months old. It was 12.7v with engine off.

Obviously I'm now nervous if the problem occurs on a longer journey could break down if battery isn't charging. Does anyone know if something could cause an 'intermittent' problem such as this?

Also to mention 15k miles ago the 'V-belt, tensioner and idler pullies' were replaced (main dealer) which I understand drives the alternator so hopefully that shouldn't be failing.

 

11 minutes ago, Jim_Cambridge said:

Obviously I'm now nervous if the problem occurs on a longer journey could break down if battery isn't charging. Does anyone know if something could cause an 'intermittent' problem such as this?

Your car has a Battery Charge light on the instrument cluster. If the battery is not being charged then it will illuminate to warn you. With a diesel engine your car would run for at least a half hour once the battery warning light came on which should be plenty time to get to a safe parking location.

If you are still worried then but a new alternator which is between £600 and £700 plus fitting.

5 hours ago, unofix said:

Your car has a Battery Charge light on the instrument cluster. If the battery is not being charged then it will illuminate to warn you. With a diesel engine your car would run for at least a half hour once the battery warning light came on which should be plenty time to get to a safe parking location.

If you are still worried then but a new alternator which is between £600 and £700 plus fitting.

The strange thing is, when I had the problem before (14 years ago!) I'm sure the warning light didn't come on, and I don't believe it came on on the latest occasion. I'm wondering if the issue before was one of the diodes failed but others didn't so it was still charging but at lower rate. I guessed the heat was due to a short, and the noise due to high load on the belt. But who knows, that could well be wrong.

Re alternator cost, not sure where £600-700 is from but you can get apparently equivalent (150A) alternators from around £100 new online - I can't know the quality of these obviously.

Hi all, update on my issue. Having done two short journeys with no whining sound (and battery voltage >14v) I 'tested' it by putting on heated windscreen, auxiliary heater and headlights... seemed to trigger it, whining sound, and very quickly alternator was hot (could smell it when opening bonnet) and approx 12.5v on battery with engine running. However the battery warning light does not come on, same as when I had apparently same problem on my previous car. I tried two restarts without the extra load and same, so definitely a problem that needs fixing. I tried unplugging the 3 pin plug on alternator, battery warning light came on but still whining sound.

My question (for the experts on here 😀) can I safely assume this is an alternator issue - which it was previously with same symptoms - and go ahead with replacing it?  

Looking for some help again, I'm pretty fed up as I got a reman alternator (from Rotating Solutions via ebay), spent a lot of time and hassle fitting it, and the problem is still the same, soon as I started the car the whine was there, and battery wasn't charging, showed around 11v. Alternator seemed to be getting warm although I didn't run engine for long.

Can anyone suggest what to check before I give in and take it into the garage? I know there is possibility of the reman alternator being duff but seems unlikely, seller got very good feedback and symptoms are same as old alternator.

32 minutes ago, Jim_Cambridge said:

Looking for some help again, I'm pretty fed up as I got a reman alternator (from Rotating Solutions via ebay), spent a lot of time and hassle fitting it, and the problem is still the same, soon as I started the car the whine was there, and battery wasn't charging, showed around 11v. Alternator seemed to be getting warm although I didn't run engine for long.

Can anyone suggest what to check before I give in and take it into the garage? I know there is possibility of the reman alternator being duff but seems unlikely, seller got very good feedback and symptoms are same as old alternator.

Look for a broken wire between the alternator plug and the PCM.

Thanks Tom, I'm not sure how to do that check, would it be visual or electrical continuity? 

Some other info, firstly when I disconnected the small 3-wire plug from alternator, the whine was gone, but battery still did not charge.

Secondly I did the 'basic' meter diode test I found on youtube (disconnected both cables from alternator) which gives around 0.5v when +ve meter connection on ground, -ve meter connection on positive alternator output. Other way round (+ve meter to +ve, -ve meter to ground) was open/OL - which video said it should be.

When I did same test on old alternator, it showed around 0.5v both ways, which suggests the old one was faulty?

Wondering if related to battery. I fitted new one 2 months ago (I started another thread on this about 2 weeks ago). I still have old battery which was working when I took it out, am charging now then tomorrow will try in car.  

Visual check first.  If nothing found then continuity and insulation resistance test.  If the insulation is damaged from two wires rubbing together that could cause a short even without the plug connected.  However that does seem unlikely if it's not charging even without the plug in.

Which battery did you buy?  I'm guessing it's not Silver Calcium as those are so hard to find nowadays?

Is the clutch pulley definitely working?  Not slipping which would spin the alternator at fewer RPM than the engine?

I did a brief visual check previously and couldn't see anything wrong but not sure what I'm looking for, cable is in a ribbed conduit protecting it (control wires we're talking about). Continuity I wouldn't know where wires go to, am trying to understand what I've been reading about L, IG, C connections, apparently Light (dash), Ignition (switched 12v), and C (control to PCM?) but not sure it will help....

The new battery is Bosch S4 007. Didn't say it was silver calcium (AgCa). I've read conflicting stories, some say most batteries are AgCa but not stated as such, others like you (Tom) say they're not widely available. My previous battery was Bosch S5 007 which is being advertised here https://advancedbatterysupplies.co.uk/product/bosch-silver-100/ as AgCa but other sellers don't state the S5 007 as AgCa.

I'm pretty sure it's not a mechanical issue. I had the pulley mechanism out for the job and it felt and looked fine, belt good too, was changed about 20k miles ago. 

12 hours ago, Jim_Cambridge said:

I did a brief visual check previously and couldn't see anything wrong but not sure what I'm looking for, cable is in a ribbed conduit protecting it (control wires we're talking about). Continuity I wouldn't know where wires go to, am trying to understand what I've been reading about L, IG, C connections, apparently Light (dash), Ignition (switched 12v), and C (control to PCM?) but not sure it will help....

The new battery is Bosch S4 007. Didn't say it was silver calcium (AgCa). I've read conflicting stories, some say most batteries are AgCa but not stated as such, others like you (Tom) say they're not widely available. My previous battery was Bosch S5 007 which is being advertised here https://advancedbatterysupplies.co.uk/product/bosch-silver-100/ as AgCa but other sellers don't state the S5 007 as AgCa.

I'm pretty sure it's not a mechanical issue. I had the pulley mechanism out for the job and it felt and looked fine, belt good too, was changed about 20k miles ago. 

I would expect all 3 wires to go to the PCM.  The information from those will then get relayed between PCM/GEM/HEC over CANBUS.  I doubt a car of this age still has a direct wire from the alternator through to the dash light.  @unofix may have wiring diagrams for these.

Most batteries aren't Silver Calcium.  But a standard lead acid battery will still work on these - just not as well and not for as long.  I was more interested to see whether you'd fitted a totally different type such as AGM but the S4 should still do the job.

If you're sure it's not a mechanical issue, and leaving the small plug off makes no difference, then the only thing I can thing of would be the main cable connections.  Perhaps a weak ground cable somewhere?  But if that was the case, I would expect issues with the starter as well.

Thanks again Tom. I tried old battery today (charged it first, had good voltage) and was same. I will try to check continuity of 3 pin connector wires, need to work out where they go. There is no ground wire, it must be via chassis/engine, could be that, I tested resistance from ground to alternator case and that was low I think 0.1 ohm at least some of that would be meter leads/connectors, but that does obviously need to be very low resistance with 10's of amps. I will try grounding alternator case with a jump lead to be sure.

Here are a couple of schematics for the Focus 2008 and 2010 which may help. They are not the easiest of circuit diagrams to follow since they are from the days before the new active schematics.

Focus ST_C307 2008.pdf Focus EU_C307 2010.pdf

3 hours ago, unofix said:

Here are a couple of schematics for the Focus 2008 and 2010 which may help. They are not the easiest of circuit diagrams to follow since they are from the days before the new active schematics.

Focus ST_C307 2008.pdf 12.94 MB · 0 downloads Focus EU_C307 2010.pdf 6.49 MB · 0 downloads

Page 326 seems to be the one for 1.8 TDCi (marked as generator). Line 3 tested continuity to Fuse F31. Other two lines Alt Mon G3 C419 and Alt Com D1 C418 I'd have to work out how to test to PCM/ECU. Hopefully not faulty PCM.

For anyone still reading, I (carefully) did open circuit test i.e. with positive wire to battery disconnected. The output voltage at idle was 1.4v, with or without the 3 pin connector plugged in. I would have thought it should be much higher, but maybe it would always behave 'incorrectly' with no battery connection. 

Alternators need the excitation voltage & current provided by the battery before they will deliver any output. This is sent to the rotor through slip-rings to create a rotating magnetic field. That generates a 3-phase alternating current in the stator that is rectified by a diode bridge. Output control is normally done by the regulator rapidly switching the rotor supply on and off. I imagine the regulator is either bypassed or influenced by the signal from the BMS on the 3-pin connector, that's a guess though.

I've just paid an auto electrician £65 to take under 10 mins to diagnose the replacement alternator is faulty. Obviously I'm pretty annoyed. Don't know if I have any rights to claim back cost of diagnosis from supplier plus obviously what I paid for alternator. That would still leave me 5-6 hours of work out of pocket...

1 hour ago, Jim_Cambridge said:

I've just paid an auto electrician £65 to take under 10 mins to diagnose the replacement alternator is faulty. Obviously I'm pretty annoyed. Don't know if I have any rights to claim back cost of diagnosis from supplier plus obviously what I paid for alternator. That would still leave me 5-6 hours of work out of pocket...

That's frustrating but at least you've got a firm answer now.  I also had a bad refurbished alternator a few years ago and would never buy another refurb again.  I'd rather buy a good used one from ebay or a breakers instead.  Unless you intend to keep the car for many more years, then brand new branded might be the best option.

To the credit of the supplier, they've agreed to send me a brand new alternator at no additional cost. Still very poor they didn't test the other one properly. Slightly ironic as the car is at 201k so I suspect it won't be running many more years. You say get one used or from a breakers but that could be close to failure or possibly even dead, they may not have tested. If it wasnt such a fiddly job to fit it wouldn't be much of a risk.

To finish off the story, I fitted the brand new alternator (plus line brand), and now working, so seems it was indeed a faulty recon alternator. I had a brief moment of dread when I first started engine, red battery warning light stayed on for  8-10 seconds - no idea why - but after that it seems fine and have 14.5v at battery.

I did have another annoyance, the new alternator had a gap between the top mounts about 1mm wider than the engine mounts (and the old alternator), I managed to locate a very thin washer to insert in the gap (harder than it sounds) to stop it being a bit loose. Hopefully there won't be any more to this story to post here!

My personal recommendation for anyone else with same problem, firstly don't ignore any whining sound, and stop straight away if you can. Either the diode/rectifier part for about £30 and fit to old alternator (good video on youtube) if you caught the problem quickly and didn't overheat alternator too much, which might have burnt out windings or something, or buy a new alternator - quality/price dependent on how long you expect the car to last.

Tips for fitting:

Have a small (short and thin handled) 1/4" socket wrench to get to the top alternator bolt, and a M8 bolt (suggest at least 30mm length) for the tensioner

Aircon compressor, tie it to pull it away from pulley (towards passenger side) to get good access, otherwise it will be in your way both for view, getting access and turning the wrench. And may only be 3 bolts (not 4 as Haynes says)

3 bolts on tensioner (not 2 as Haynes says)

Have two people to take out and refit alternator, take the old one out from bottom, and put the new one in from the top, both are tight fit and will need to rotate and pull hoses around to get it into/out of place. And to confirm, this was on a 2009 Mk2.5 1.8 TDCi.