MY FOCUS MK2 , WHILE DRIVING CAR YESTERDAY, BATTERY LAMP ON, FRONT SCREEN AND REAR SCREEN HEATERS START WORKING AND HAND BRAKE LAMP GONE ON IN DASH, I STOP THE CAR AND START IT AGAIN AND LOOK BATTERY FROM DASH , IT WAS AROUND 16.5 CHARCHING AND I PULL OUT CHARCING CABLE , AND DRIVE MY CAR 50KM TO MY HOME, BUT THERE WAS NO BATTERY LIGHT IN DASH WHEN I PULL OFF CHARCING CABLE FROM ALTERNATOR , THEN I BUY TWO WORKING ALTERNATORS FOR MY CAR AND I TRY BOTH OF THEM ON CAR, BUT THEY ARE SAME , THEY ARE CHARCING HIGH :(

WHAT IS THE PROBLEM WHERE IS IT ???

I LOOK ALL CABLE FROM BATTERY TO ALTERNATOR , THEY ARE IN GOOD CONDITION, IS THERE ANY PROBLEM WITH FUSE BOX ???

OR ANY PROBLEM WITH PCM SOCKET ???

The Focus is equipped with a Smart Charge alternator. For this type of alternator the charging of the battery is controlled by the PCM based on the temperature and voltage of the battery

If the (3 wire) connector of the alternator is removed (like you already did) the Smart Charge alternator starts working like a normal type of alternator. In your situation the alternator seems to work correctly if the connector is removed. It is most likely the problem is caused by faulty wiring between the alternator and PCM or in worst case a faulty PCM.

I think your next step would be checking the wiring between the alternator and the PCM. It is a known problem that due to vibration the isolation of the wires in the wiring loom is damaged which can result in a short circuit or open circuit of the wiring.

A bad battery can make a lot of strange faults - try replacing it?

thanks a lot ..

ı try it with new battery but it is same :(

now ı will look cables between alternator socket to PCM.

I belive I have read that it is not unormal for the alternator to put out up to 16,5V charging voltage - the Silver Cadmium (or Cadmium) battery have no problem with a so high charging voltage.

But a 16,5V charging voltage will only happen under special circumstances - as mentioned - the PCM reads temperatur in air, coolant, etc.

So it would be good to check every electrical contact in the engine room - with a faulty electrical contact the pcm may believe your car are in freezing conditions and in special need of a high charging voltage.

the red cable on alternator socket and battery are not at the same voltage, i read that they sould be at the same voltage , but where is the problem ??

and i cant remove the PCM socket , how can i remove it ??

In the Haynes Manual it says you have use a drill to remove the pcm socket.

Did You check fault codes?

ı cant look for fault codes now, but when i playing looking to cables now central locking not working from key buttons :(

how it could be ???

and i reset PCM from laptop, but its same :(

Maybe checking the big cable-sockets on the fuse-board inside the car? Under the glove compartment.

The can get loose and cause a lot of strange problems.

i look all off them , but there is nothing , alloff them ok. , i cant find any broken socket or cable .

now central locking not working from key buttons , how it could be ??? i play with PCM cables between alternator and its not working

if its charging at 16.5 with a new alternator and a new battery then the fault lies in any one of half a dozen sensors or in the ecu it may even be damaged wiring the truth is its not something you can find at home it all needs specialist equuipment it sounds like the smart charge wiring

i found it , it si wiring problem between alternator and fuse box under hood, alternator pin and battery voltage is not same , and ı look wiring , then i found that the cable between alternator and fuse box is damaged, i change the red cable , now it is ok..

and ı have one questıon , when i push stop , the battery voltage decrease to 13.7 voltage, is it normal ???

its 14.1 while working the engine.

and engine is working at 800 rpm, is it ok ???

Rpm is fine if tge battery was disconnected the car has to relearn 14.1-14.4 v is normal 13.7 when stopping sounds okay as long as its brief and it goes bsck up to 14.4

when i look battery in dash, it is 14.1 or 14.2 , but when i push stop , it decrease to 13.7, and when i pull back my foot it shows 14.1 again , is it ok ???

and at the night time , when i open all lights on car and front and rear windows heaters, and then push to stop , battery decrease to 12.1 v , and lights effects decrease too, is it same at yours focus ???

Yes its fine you shouldnt really run the front heater it draws too much power you should only put on lights and rear window heater and get 13.7 or above

ok ım try it now

I have done what u said and ist ok.thank you

I had a snapped wire on mine a few years back now...some people will remember.

Anyways if i start the car, turn the lights on, radio on heated front and rear screen the lights do dim...But will get brighter when you are driving as the alternator is able to spin faster and produce the power required.

I remember that one JohnH, it was a bit of an expensive time as I require, new battery, new alternator, and several trips back to Jennings?

oh yes and counting the time me and mate had the whole engine harness out checking.... couldnt figure how to access the ecu as i thought it was in the wheel arch and some body work had to come off... i was wrong lol

tell you what though mate, ford must have an abundance of electrical tape...has anyone noticed how much they actually use???

But yeah i could of ended up witha good ford battery as spare as i current have a bosch S5 in mine now and i still have the old alternator, which no doubt will be still good.

On ‎02‎/‎07‎/‎2013 at 6:16 PM, johnH said:

oh yes and counting the time me and mate had the whole engine harness out checking.... couldnt figure how to access the ecu as i thought it was in the wheel arch and some body work had to come off... i was wrong lol

tell you what though mate, ford must have an abundance of electrical tape...has anyone noticed how much they actually use???

But yeah i could of ended up witha good ford battery as spare as i current have a bosch S5 in mine now and i still have the old alternator, which no doubt will be still good.

Hi all

I think I have a problem with the wiring between the alternator and the PCM.

I'm looking to just replace the two cables (the grey and the blue) from the three way plug on the alternator (the other is fine, being the 12 v permanent), to the PCM, as I'm getting 10 ohms to ground on the grey lead.

My question is, where should I be looking for the PCM box? Is it in the glove box area? There looks to be lots of electric-ary going on there!

I've searched and seen mention of pins 59 and 72 for the grey and blue respectively. Does that sound right?

2007 Focus 1.6 tdci climate estate manual.

Thanks everyone. :)