I bought a 05 reg ka accident damage a while ago, repaired the front end but the alternator had damage and two of the wires to it was traped to the body, repaired the wiring and replaced the alternator but the charge light was still on dash and the battery wasnt charging (start the car, it goes out then after 20 seconds it illuminates). nxt i sent it off to auto sparky who diagnosed it as a ecu fault, fitted a recon one at £190 but still no joy and told me the alternator was also shagged!! so i picked the car up tonite and battery was flat tow started it and it seemed to run fine starting up running all the electrics all nite but the battery light was still lite, then it died once, got it going again and then its been fine again, any ideas much appreciated as im not sure if this electrition is trying to fleece me for more cash or not and the car is doing my head in!! cheers matt

 

Try putting a multimeter on the alternator to see if thats putting out any power

Adam

 

Disconnect the charge warning light wire from the alternator then start car, put metre on battery not reading touch a LIVE wire from battery onto the alternator charge terminal, the engine note will dip very slightly and the volts should rise.
The alternator uses the LIVE through the bulb to initiate the charging process, when it excites the field windings in the alternator and starts charging it then outputs 12v down the terminal(charge light) and so puts bulb out, as two lives don't make a bulb light.
With this method you can watch the actual difference between running with no charge and charging.
tabetha

 

depending on which version you have, most newer fords have had the voltage regulator built into the ecu as of the past few years

we went through this with my mates focus with the alternator guy scaring him into thinking the ecu was buggered when the alternator was showing it was fubar
it was fubar and we swapped it over but the light came back on again in a matter of minutes
then went to ford to find out and thats when we found out about the wiring problems that loads of cars were coming in with

so make sure you get someone who knows what they are talking baout if you take it into ford about this, althoguh if the wiring in the wing has been damaged then it might be the cause, but then again, if the loom is run different on the ka to the focus then it might not be the same problem at all

 

If it is the same as the Focus, it runs a Smart-charge system, controlled by the ECU as Dojj says. The recall the Focus's (mainly ST170s) were coming in for was a 1-way diode in the wiring which was blowing. A lot of techies were getting told off as they were changing looms under warranty for £xxx instead of a 70p diode

BTW: the battery warning light is controlled by the ECU, not connected to the alternator on most Fords after 2003/4.

 

Another up to date shitty idea then to fleece more money!!
You could always put an older one on that works the old way.
tabetha

 

or you could just disconnect the 2 wire plug then the alternator should work as per normal.

sounds like a broken wire to me.

transit connects are common for it as the cable ties around the loom are simply too tight!

 

thanks for all the responses with this one, it is a ecu controled alternator apparently, it has the main out put wire to the battery and a plug with three wires going to it. does any one have any idea where the one way diode might be??