Tin top is a Ford Mondeo TDDI. 2 litre diesel 2001 vintage and just clocked over 213,000 miles.

Out today dropping the relatives back home and the charge light came on. Had similar once before when alternator burnt out, sure enough had a smell of very hot wiring but was not in any place I could pull over and stop. So decided that unless I ended up with smoke pouring from the bonnet I would keep going. Had to stop and switch off engine at a nursing home. Did the drop off and about 30 mins later came back to the car.

All warning lights on before start of engine and all off when running, including the charge light.

Managed to get home without any issues, had a check of the battery voltage and on revs the voltage rises to 14.6 volts and around 13.8 to 14 volts on tick over. So it looks as though the alternator is still putting in charge.

Now regulators and electronics do not suddenly fix them selves. There is a burnt smell around the alternator, but the fact of the smell and the charge light being on for a good 8 miles has me wondering what happened?

Adrian

[Edited on 26-12-13 by AdrianH]

I have never had that problem but I can think of a scenario where it could happen. Imaging one of the 6 cells went s/c. The alternator will then go to max charge 100A in a modern alternator. The cell warms up the temporary s/c disappears and all returns to normal. I would be tempted to put a volt meter across the battery and drive it around for a while.

Is the belt ok? is one of the idler pulleys or the alternator bearings starting to seize up?

IIRC the Mondeo uses a smart alternator controlled by the ECU, disconnecting the small
Multiplug it reverts to a non smart alternator. might be a faulty mufti plug connector if your lucky.?

Seized bearing ?

I did look at the belt for signs of rapid wear and came across no cracking or glassing of the surfaces, never heard any squealing sounds to suggest a stuck pulley or bearing giving up. But that is not to say it is not.

The battery is less then 12 months old and there was no signs of dash dimming.

Looking at the following circuit , I am wondering of one of the sections of diode went short and now one coil has gone open circuit removing the short.




So basically I now only have a two phase alternator?

Adrian

Rusty Nuts prompted me to look at this Ford builtin:

http://www.valeoservice.com/data/master/webfile/2945759434DDE6E8714173.pdf

I had no idea alternators got that clever another reason to hate modernn cars when they go wrong. The bulitin does give useful diagnostic information.

The Haynes manual says it is a Lead calcium battery not a silver calcium so would suspect my 12 year old car is pre this bulletin. But who knows.

Adrian

Now sorted new alternator --Ouch!

Adrian