I'm getting a bit desperate now, I hope someone can help me...
I've got a Fiesta 1.8D, 1996. Earlier this week, the charge warning light came on (well, half on) whilst driving home. It was also obvious the thing wasn't charging, as my lights had faded by the time I got home.
I started looking at it his morning. I disconnected the alternator completely, and (perhaps fortunately) noticed that the charge warning light was still glowing, partly. My understanding is that it shouldn't do this, as the current that goes through the warning light goes through the alernator field coils to energise it.
The voltage at the alternator end of the field wire is only about 6, and this never seems to vary, whether the engine is running or the engine is stopped. Again, my understanding is that this is wrong, and while the field voltage may be about 6 when the alternator is stopped, it should go up to about 12 when the alternator is running.
I've tried to check the wire from the warning light to the alternator but the wiring diagram shoes a diode in it, and my meter won't read the resistance properly. It does show continuity as OK. (And another problem I've spent hours trying to solve: where the hell is this diode? I can't find it to check it.)
Finally, I briefly tried a wire straight from the battery live to the alternator field connection and this started the alternator charging. This tends to make me think the alternator ISN'T faulty, so I'm loathe to shell out for a new one just yet.
Can anyone assist with a diagnosis, and save me some £s, I hope.
Regards Chris
BTW, if my email address needs correcting if you want to use it.