I have Ford Focus TDCi 2005.
Recently I noticed that the Ignition/battery warning light on the Dashboard, illuminated after a few miles driven. Always the same pattern now, earlier (3 days ago) the light just came and went.
I checked the belt and tensioner and all was in very good condition.
I measured the volt on the battery cables on idle and headlights and heater on, measured it to 13,5 to 14 Volt.
When searching for solution on the Internet, I found that the 3 wire plug can cause this, computer may be the problem, I did check this plug and wires, it was clean and fine.
The workshop and Ford dealer here could not confirm that the alternator was failing, maybe the diodes? Then again it produces fine volts.
Could it be the computer reading? I did try to reset the computer but the light did illuminate again.
I could try to replace the diodes, but it gives 13-14 volt......

Just in case: Can anyone help my finding unrated diodes or even rebuild alternator for a reasonable price (I believe it is Denso 120 amp)?

Any good advice's greatly appreciated

(are there any other specific "Focus-Diesel forums" I could ask in?)