Hi all,

Ok so yesterday on my way to work the battery light came on , i had already brought a new one but not fitted it yet . So i turned around went home and fitted it. After a few minutes the light came back on...BAH . I had to go to work now so i risked it and got to work and got home , no apparent issues , battery light was on all this time too. I didn't get home till midnight so i left it till the morning to whack the old multi meter on it. 

I got - Engine off - 12.7v

Engine on - 13.58v / but at first it was 14.5v then dropped to 13.58v with only the engine running

Engine on and lights , heater on 2 , and stereo - 11.98v

Ive been looking on line and i cant find a solid answer to " is my alternator on its way out " ?

Anyone able to shed any light or had the same issue ??

The car is a 2009 focus cdti 1.6 zetec

 

Cheers in advance...!

Unfortunatelly, yes! Alternator is not able to sustain the load. Before next start enter the diagnostic mode, start the engine and reach for the battery voltage measurement on the diagnostic. Vary the load (lights on, off, vent fan off and on, rear window heating off and on-this one is really HD test) and read out the voltage measurement. When loaded fully, voltage should not drop below 13.95V .

 

OK  , im guessing its time to replace it.

Next question is how ? i cant find any videos online etc ?

Right, check this first, there are few possibilities:

- auxiliary belt,

- generator coupling,

- generator itself

https://workshop-manuals.com/ford/focus_2004.75_07.2004/mechanical_repairs/4_electrical/414_battery_and_charging_system/414-00_charging_system_general_information/description_and_operation/diagnosis_and_testing/charging_system/

i think its the original one tbh , so its 10 years old almost . I dont really know what im looking at with what you mentioned , so i think im just gonna get it changed . i can get the alternator and belt swapped out for £170

 

I own a 15 yrs MK1.Recently I purchased a voltmeter that plugs into the cig/aux socket so that I can monitor any abnormal voltage changes.Accuracy of the gadget is slightly out according to my portable voltmeter but it gives me a rough idea of what’s happening rather than opening the bonnet all the time👍

i think with it dropping to 11.9 v ish when i had the lights heater and stereo on  , that would be most normal driving conditions , including the engine running . I thinks its safe to say its on its way and it cant keep it supplied with enough voltage to charge what im using . Its a brand new battery and i guess using the car in this way is bad for it .

With the heater on my plug in voltmeter reads 14.2volts👍

See the difference , mine drops below 12....not good

 

 

Absolutely a flat battery is looming👍

Just take it easy. First, auxiliary belt need to be replaced after 10-yr's or 120 k miles. At the same time, check that alternator is spinning freely, no strange noise, no clutch damage etc. also check that cables from the battery are not corroded (especially minus connection to the engine and car body).

 After new belt is installed, try starting the engine, check voltage on load (lights, vent, rear window heater etc..). If there is no change, than go for the alternator. BTW when did you change your cam belt ? Battery is the least of the problem, re-charge it using external charger.

ive not yet .

Ive had it 3 years in sept and its done 95.5K

Not sure if it was changed before hand but i dont think so

 

Also there is a kinda whirring noise from that side of the engine ( alternator side) Which is quite new .

Occasionally in the morning  my aux belt slips giving a reading of 12 volts but normally the reading is 14.6👍

3 hours ago, tonydb said:

Also there is a kinda whirring noise from that side of the engine ( alternator side) Which is quite new .

Well any way you turn it, belt goes first, than alternator clutch.....