54 plate, battery light comes on 20 secs after starting up and stays on, wiring to alternator is fine, what else could i try

claire linton, April 2008

The battery light came on on my friend's Ford Ka a week ago. Battery seemed to be fully charged at 12.5V, alternator was putting out 13.5V. (Battery light comes on if voltage drops below 13.8V.)

Jacked up the front of the car, took off the front wheels, removed the front bumper and plastic trim round the wheel arches. This was held on with a mixture of torx screws, phillips screws and white plastic clips (the clips can be squeezed with pliers to get them out without snapping). Once the bumper was off there was enough access to the three pin plug on the alternator to remove it by *gently* prising against the plastic clip with a flat headed screwdriver and sliding it off. The back of the plug had three wires - orange and red, blue and grey. The blue one was broken off tight against the connector for pin 2. The pins for the connector plug are numbered on the back and are:

Pin 1 = Alternator Feedback
Pin 2 = Alternator Load Request
Pin 3 = Reference Voltage

without the alternator load request pin connected the alternator converts to a conventional mode, not 'smart charge' although the other mechanicals of the alternator work fine.

Went to the Ford dealer and bought Ford Connect part no.1421293 This is actually a Ford Transit part but includes the same three pin connector as the broken one for the alternator, about a foot of wire and another type of connector that wasn't needed.

Back on the Ka, disconnected battery (-)ve, pulled back the black plastic around the wiring and cut off the old three pin connector where the wires looked less corroded, leaving a little bit of each wire free. Then cut the new part in half to get a new three pin connector with three wire tails that could be attached to the three wires on the Ka with wiring snap connectors. Noted down which wire went to which pin on a notepad for this bit to avoid mix-ups.

Electrical taped round the connectors and the top of the new plug where it attached to the alternator to keep water out and stop the problem happening again. The alternator now charges at 14.2V, battery light switched off. Took 1/2 a day to fix.

Paperfrogs, June 2012

found out 2 wires were loses fixed in 15 mins,thanks for the tips and hints.

jim, May 2012

It may be warning that the battery is not charging but in most cases the batter is charging, an its pretty easy to see if the belts broke as it will not be there,
Check the Blue wire from the alternator as this send the feed to the battery light.
Also as has been previously mentioned ford do a connector repair kit for around £15-£25 as this connector becomes corroded

Scott, April 2012

Can anyone tell me how to remove the smart plug, i can't quite see how to do it.!

chrisi, October 2011

I work at halfords and i have tested my parnters battery and alternator and both are amazingly fine, i have been told that a dodgy bulb wiring can cause the battery light to come on in my partners car when you drive along at night the speedo light flickers ever so slightly and so do the headlights. i find that when my partner accelerates hard the light goes off such a random thing.

craig b, September 2011

leave the 3 pin plug disconnected, it will still charge 13.8 volts ,tape over the charging light (if it annoys you)the engine management light will come on and warn you of any more alt. or belt problems mine has run like that for ages

halfday, May 2011

My sisters 03 ka has this fault ive replaced the wiring plug and the 3a fuse in the back of the fuse box the alternator and wiring all the way back to the suspension turret. light still comes on 2 codes stored in ecu P1632 & P0620 both ref smart charge/alternator
only way to go is to get it scoped up now. pin 1 is bat + pin 2 is command from ecu and pin 3 is return commant to ecu i feel the fault lies there for everyone...
its either a resisting cable on the voltage dropping out the system or a signal wire is broken.

mobilediagnostic at live.com contact me if you need the light checking or the faul codes erasing OR if you know how to repair the problem

mobile diagnostic service west yorkshire, March 2011

So if my alternator is ok like my uncle said, what could be wrong and should i just get a brand new one?

Jay, January 2011

Im having the same problem, my light keepps coming on and going off again a few times when im driving in it, also im having problems with my power steering, it has gone very stiff when i turn a corner and i have to pull it back or it will just stay there, mine is an 04 silver KA, does anyone have any advice about fixing both these problems? and how much it may cost? please email me.

vicky drage at hotmail . com
I am in my last year of nursing and i really need my car to work! so all advice welcome.
thank you x

Victoria Drage, January 2011

ive had a new alternator on my car today, battery is fine and charging at 13.5 vaults however the battery light remains on!

Has any body had this problem before or experience with it.

Quick and easy solution is needed as i am returning ot university tomorrow and need to drive back in it.


Email me: (put email normal)

miss_hannah_hunter at yahoo dot com

with your answers pleaseeee

thankyou

hannah

hannah, February 2010

your alternator is behind the grill at the front its a little black box my 53 plate had the same thing it was only when i broke down when the rac came out 2 it he saw it the wires was out of the alternator u can get a alternator repiar kit from your ford dealer it £15.00 but let them fit it thats £65.00 the wires were mouldie so they had 2 take the front of the car off but its bin a month and its not come back on thank god lol

craig, September 2009

went 2 motorsave they said it could be wiring or electrical or the alternator but the car works fine so why wont it go off?

craig, August 2009

My sister also has this problem on her 52 1.3 duratec ka.
So far i have replaced the alternator as i believed the 'smart charge' system to be at fault ive also replaced about 3" of the wiring loom and the connector to the smart charge module on the alternator.
I have code read with an obd2 scanner - nothing.
cade read with a proper scanner and in there were codes for the smart charge... clear them and they come back... i suspect an ecu fault or some wiring fault - but how to fix it i do not know.. she said it first came on after going over a big speed hump

flash auto electrics, August 2009

common fault in kas. Check the wire leading to the alternator.

shottsjohn, March 2009

drop down the fuse box and check 3 amp fuse has not blown.

lee, August 2008

Its warning you the battery is not being charged, so it could be an alternator fault or a drive belt problem or a dodgy connection on the warning light itself.
If you are unsure take it to an auto electrician rather than a garage & save a little money

Dave, April 2008

I have same problem, I changeed altonator and belt costing me £180 and the light came on 20 seconds after I started it up again.

Mark., April 2008

Claire, see your previous question either the drive belt has broken or the alternator is duff

nigel, April 2008