focus battery light stays on

emmbaasee

hi guys.
99 focus 1.6 petrol.
the battery light comes on after i start it and stays on.
checked the battery on my meter and its reading over 13 volts.
i also checked the alternator and its reading over 13 volts.
i put in a new alternator to see would this solve the problem and no joy.
heard a clicking noise coming from the main fuse board behind the clove box and it turned out to be a relay switch that was labelled in the handbook as being a battery saver relay switch.
changed that and the light is still on
ive read various things on the web about similar probs but nothing is exactly like mine it seems.
battery is overcharging perhaps ?

anybody got any suggestions?

thanks

Nissan doctor

Was it a new alternator or a second hand one? Your battery and alternator should be reading over 14v in normal operation.

emmbaasee

Nissan doctor wrote: »

Was it a new alternator or a second hand one? Your battery and alternator should be reading over 14v in normal operation.

it was a 2nd hand alternator

Nissan doctor

I had a feeling, ford alternators regularly give trouble so chances are the second hand one has issues too.

emmbaasee

Nissan doctor wrote: »

I had a feeling, ford alternators regularly give trouble so chances are the second hand one has issues too.

do you think a new one is the way to go ? new batt also ?
i hate throwing good money after bad.
i was thinking of getting a 2nd hand ecu and seeing would that get rid of the light ..

listermint

emmbaasee wrote: »

do you think a new one is the way to go ? new batt also ?
i hate throwing good money after bad.
i was thinking of getting a 2nd hand ecu and seeing would that get rid of the light ..

The ECU wont change the voltage reading you are getting from both the alternator or the battery.

My friend went through x2 alternators on his 05 Focus. The seem to be terrible.

Nissan doctor

emmbaasee wrote: »

do you think a new one is the way to go ? new batt also ?
i hate throwing good money after bad.
i was thinking of getting a 2nd hand ecu and seeing would that get rid of the light ..

Changing the ecu because of a battery light would be throwing a lot of good money away for no reason!

You could have your alternator rebuilt by an auto electrician, this would be the cheapest option but you need to get the charging system checked properly to be sure of the problem.

emmbaasee

can anybody tell me is the voltage regulator within the altenator or where can i find it ?
this is another theory i have that might be causing the light to come on.

Nissan doctor

emmbaasee wrote: »

can anybody tell me is the voltage regulator within the altenator or where can i find it ?
this is another theory i have that might be causing the light to come on.

Yup its part of the alternator..

jimmyw

emmbaasee wrote: »

hi guys.
99 focus 1.6 petrol.
the battery light comes on after i start it and stays on.
checked the battery on my meter and its reading over 13 volts.
i also checked the alternator and its reading over 13 volts.
i put in a new alternator to see would this solve the problem and no joy.
heard a clicking noise coming from the main fuse board behind the clove box and it turned out to be a relay switch that was labelled in the handbook as being a battery saver relay switch.
changed that and the light is still on
ive read various things on the web about similar probs but nothing is exactly like mine it seems.
battery is overcharging perhaps ?

anybody got any suggestions?

thanks

Was it a new alternator or a second hand one? Your battery and alternator should be reading over 14v in normal operation.

Do focus's generally produce over 14 volts from the alternator? I would have thought that the voltage in the OPs would be ok.I thought ford use some kind of a smart type charging systems.

lifer_sean

Before you do anything wild, check if the car is actually charging. With engine off, battery voltage should be about 11.5-12V. When running, voltage should rise by about 2 volts, ie 13.5V - 14.5V.

Are any of the other warning lights or gauges acting funny on the dash ? The instrument cluster is prone to problems on these. Leakage on the back of the pcb due to corrosion can cause false warning lights, jumpy gauges, etc. Cleaning PCB usually fixes (no parts needed).

emmbaasee

jimmyw wrote: »

Was it a new alternator or a second hand one? Your battery and alternator should be reading over 14v in normal operation.

Do focus's generally produce over 14 volts from the alternator? I would have thought that the voltage in the OPs would be ok.I thought ford use some kind of a smart type charging systems.

not sure about the 14 volts thing but i would have thought that a little over 13 would of been enough.
I really dont think its the alternator or batt but i just cant be sure.

maidhc

Nissan doctor wrote: »

Yup its part of the alternator..

Im not sure with the focus. It has a smart charge system and a freewheel clutch on the alternator. I think the ECU controls the voltage in normal operation, but there may be a backup on the alternator.

I doubt fitting a new ECU will solve anything though.

emmbaasee

lifer_sean wrote: »

Before you do anything wild, check if the car is actually charging. With engine off, battery voltage should be about 11.5-12V. When running, voltage should rise by about 2 volts, ie 13.5V - 14.5V.

Are any of the other warning lights or gauges acting funny on the dash ? The instrument cluster is prone to problems on these. Leakage on the back of the pcb due to corrosion can cause false warning lights, jumpy gauges, etc. Cleaning PCB usually fixes (no parts needed).

battery is reading 11.9v with engine off and 13.4/6 while running.
no other lights on the dash are acting funny.

Henry Ford III

emmbaasee wrote: »

battery is reading 11.9v with engine off and 13.4/6 while running

Still not high enough. Batteries are under huge performance pressure in winter.

Plug

emmbaasee wrote: »

hi guys.
99 focus 1.6 petrol.
the battery light comes on after i start it and stays on.
checked the battery on my meter and its reading over 13 volts.
i also checked the alternator and its reading over 13 volts.
i put in a new alternator to see would this solve the problem and no joy.
heard a clicking noise coming from the main fuse board behind the clove box and it turned out to be a relay switch that was labelled in the handbook as being a battery saver relay switch.
changed that and the light is still on
ive read various things on the web about similar probs but nothing is exactly like mine it seems.
battery is overcharging perhaps ?

anybody got any suggestions?

Its not always the alternator, the battery can cause the light to come on as well.
thanks

emmbaasee wrote: »

battery is reading 11.9v with engine off and 13.4/6 while running.
no other lights on the dash are acting funny.

I'd replace the battery anyway and see how you get on.

jimmyw

emmbaasee wrote: »

battery is reading 11.9v with engine off and 13.4/6 while running.
no other lights on the dash are acting funny.

Henry Ford III wrote: »

Still not high enough. Batteries are under huge performance pressure in winter.

I agree.The above voltage is not enough to even start the car.Maybe the smart charging is detecting a fault in the battery and given the warning.I dont really know much about that smart charging setup though.

emmbaasee

Sorry. Battery is reading 12.9volts when off.
im after hooking the car up to my wifes battery and the light has come back on.
Just to confirm.The car has started no problem with my battery in it.Even on the really cold days of the recent past.
Still think its some how related to the ecu.
And no, i wont be buying a new ecu, but have not ruled out getting one from a breakers...

emmbaasee

Really dont think its the battery but its on the list of things to replace.
Cant bring myself to buy a new battery when i dont think its the problem

crosshair1

These alternators are part of a smart charge system involving the engine ecu (pcm).

The alternator is capable of functioning as a normal charge system if there is no signal from the ecu (for example diconnecting the 3 pin plug)

Before replacing any more parts it would be advisable to have codes read from the ecu.

A broken wire runnning to the alternator could cause your fault.

jimmyw

[QUOTE=

]emmbaasee;69888861]Sorry. Battery is reading 12.9volts when off.

im[/COLOR] after hooking the car up to my

wifes

battery and the light has come back on.
Just to confirm.The car has started no problem with my battery in it.Even on the really cold days of the recent past.
Still think its some how related to the ecu.
And no, i wont be buying a new ecu, but have not ruled out getting one from a breakers...[/QUOTE]

Well if its reading that when off, that is plenty of juice there to start. But when did you check that?If you check it just after she runs, you could be getting a false reading.Leave it for about 5-10 minutes. As you say if its at that then it is doubtful that it is the battery.Alternator could possibly dodgy.The link may help too.

http://www.petercoopercarrepairs.co.uk/ford_focus_alternator_smart_charging.htm

emmbaasee

crosshair1 wrote: »

These alternators are part of a smart charge system involving the engine ecu (pcm).

The alternator is capable of functioning as a normal charge system if there is no signal from the ecu (for example diconnecting the 3 pin plug)

Before replacing any more parts it would be advisable to have codes read from the ecu.

A broken wire runnning to the alternator could cause your fault.

After a lot of testing and re-testing and, i've come to the conclusion that your right.
I plugged out the 3 pin plug and im going to leave it at that. The light is still on but the car is running fine.
It's the ecu. I have no doubt.
Thanks for the help guys

Nissan doctor

emmbaasee wrote: »

After a lot of testing and re-testing and, i've come to the conclusion that your right.
I plugged out the 3 pin plug and im going to leave it at that. The light is still on but the car is running fine.
It's the ecu. I have no doubt.
Thanks for the help guys

Make sure you check the wires from the 3 pin connector, Its common for the ecu signal wire to break too..