Battery Light Flashes When Braking

[greggp]

hi all,

you may recall I have had a few issues with my focus titanium for the past 12 months (link to one issue below) since ford replaced with a new engine almost a year to the day!

anyway it went into fords a couple of weeks ago for a service and they did a PCM software update & air filter change for me.

Starting issue seems to have gone away touch wood, however have noticed an intermittent problem happening with the car since the service!

Revs drop and battery light flash upon harsh braking

Noticed a few days after the service that When I brake hard, clutch down (not emergency stop btw) but harsh braking coming up to turn into a junction for example I have noticed my revs drop really low and battery light flashes on as if about to die but then engine seems to correct itself, however it cut out on me last night as I braked to drive over a speed hump - restarted okay mind (had headlights on heated rear screen prior to it stalling).

doesnt always cut out or flash battery light on - say for instance I am driving along in traffic and slowing while approaching traffic lights the engine drops to normal revs upon stopping.

Well i've phoned ford today and re-booked it in for them to check - my initial thoughts are it could be air leak or something to do with the air filter change they did, have they possibly disturbed something near to the air filter housing??

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Idle Valve Fault Check

I also thought Idle valve may be the problem but I read somewhere that you could do a check with your car to eliminate a faulty ICV so I have just been out to car to do this.

1. Warmed car up to normal temp

2. switched all electrics on (heated rear / front screens, headlamps, air con, wipers)

3. Rev up to 3000RPM and held for few seconds.

4. Let go of pedal and watched revs drop slowly to normal idle revs

I read that if the revs drop straight to about 600RPM upon doing the above then the valve is faulty so hopefully I have eliminated it being the idle valve.

I couldnt really look to see around the air filter housing as too dark but will check at weekend.

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Dash Diagnostics Trick

I put car into diagnostics dash trick mode so I could have a look at a few other things (i.e. digital revs and battery voltage). When I did the dash trick the gauge sweep happended and the speedo needle got stuck on 80mph and wouldnt move, I turned ignition off and turned on again but needle still stayed at 80mph. turned off again and did the dash trick again got to the gauge sweep mode and needle moved back to 0. Not sure if this could have been a sign of anything wrong or not?

I also checked the battery voltage, this was reading 13.9v whilst car idling with just headlights on.

I switched air con on, heated front & rear screens, fog lights and wipers and battery level dropped and fluctuated to between 11.9v - 12.0v - presume this is because of the electrical load on it and the fact I was stationary so alternator was not turning as fast! Battery returned to 13.9 v when turning above load off.

Hopefully I will get sorted on my next visit to fords next week as I have had about enough of niggly little problems with this car.

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Link to another post of mine below

[artscot79]

hi all,

you may recall I have had a few issues with my focus titanium for the past 12 months (link to one issue below) since ford replaced with a new engine almost a year to the day!

anyway it went into fords a couple of weeks ago for a service and they did a PCM software update & air filter change for me.

Starting issue seems to have gone away touch wood, however have noticed an intermittent problem happening with the car since the service!

Revs drop and Battery light flash upon harsh braking

Noticed a few days after the service that When I brake hard, clutch down (not emergency stop btw) but harsh braking coming up to turn into a junction for example I have noticed my revs drop really low and battery light flashes on as if about to die but then engine seems to correct itself, however it cut out on me last night as I braked to drive over a speed hump - restarted okay mind (had headlights on heated rear screen prior to it stalling).

doesnt always cut out or flash battery light on - say for instance I am driving along in traffic and slowing while approaching traffic lights the engine drops to normal revs upon stopping.

Well i've phoned ford today and re-booked it in for them to check - my initial thoughts are it could be air leak or something to do with the air filter change they did, have they possibly disturbed something near to the air filter housing??

¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬

Idle Valve Fault Check

I also thought Idle valve may be the problem but I read somewhere that you could do a check with your car to eliminate a faulty ICV so I have just been out to car to do this.

1. Warmed car up to normal temp

2. switched all electrics on (heated rear / front screens, headlamps, air con, wipers)

3. Rev up to 3000RPM and held for few seconds.

4. Let go of pedal and watched revs drop slowly to normal idle revs

I read that if the revs drop straight to about 600RPM upon doing the above then the valve is faulty so hopefully I have eliminated it being the idle valve.

I couldnt really look to see around the air filter housing as too dark but will check at weekend.

¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬

Dash Diagnostics Trick

I put car into diagnostics dash trick mode so I could have a look at a few other things (i.e. digital revs and battery voltage). When I did the dash trick the gauge sweep happended and the speedo needle got stuck on 80mph and wouldnt move, I turned ignition off and turned on again but needle still stayed at 80mph. turned off again and did the dash trick again got to the gauge sweep mode and needle moved back to 0. Not sure if this could have been a sign of anything wrong or not?

I also checked the battery voltage, this was reading 13.9v whilst car idling with just headlights on.

I switched air con on, heated front & rear screens, fog lights and wipers and battery level dropped and fluctuated to between 11.9v - 12.0v - presume this is because of the electrical load on it and the fact I was stationary so alternator was not turning as fast! Battery returned to 13.9 v when turning above load off.

Hopefully I will get sorted on my next visit to fords next week as I have had about enough of niggly little problems with this car.

¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬

Link to another post of mine below

http://www.fordowner...-focus-titanium

13.9 in my opinion isnt right ive checked mine with just headlights on and get 14.3 thats the benchmark really as it should and does sit at 14.4 when you had everything on you should have revved it to 2500 rpm and see what voltage you had with it turning at engine speed heated front screen uses wads of voltage on its own and makes alternators whine just with the power it uses so ide say it may point to an alternator issue or batteryit can still be a intermittent fault on the idle control valve as well

[greggp]

hey thanks I will try doing that didnt think to try that! - just been out for a drive in it and the only time the revs dipped was under harsh braking but even then it wasnt everytime I braked harshly just a couple of times. Also I did the dash trick again and the needle on the speedo side keeps sticking at 80mph! I manage to get it back to zero buy doing dash trick and sweep again and turning off ignition. You reckon this could be related to anything the fact the speedo dial keeps sticking?

How long do altenators generally last or this dependent on numerous factors. The sheer fact that battery was disconnected a few times when the engine was replaced last year and numerous issues I've had with the vehicle maybe this could have weakened the alternator?

Will get Fords to check it all (alternator, battery & ICV).

cheers

[james_60]

Hi

I would get it checked out by someone with a battery/alternator tester.

An alternator can last longer than the car in some cases.

I have only ever replaced an alternator once and that is on my 1974 1275 mg midget and it was the original (80,000 miles over 37 years)

Jamie

[greggp]

Hi

I would get it checked out by someone with a battery/alternator tester.

An alternator can last longer than the car in some cases.

I have only ever replaced an alternator once and that is on my 1974 1275 mg midget and it was the original (80,000 miles over 37 years)

Jamie

thanks. will ford not have this equipment?

[james_60]

sorry my mind was somewhere else. yes they will. i do appologise

Jamie

[greggp]

13.9 in my opinion isnt right ive checked mine with just headlights on and get 14.3 thats the benchmark really as it should and does sit at 14.4 when you had everything on you should have revved it to 2500 rpm and see what voltage you had with it turning at engine speed heated front screen uses wads of voltage on its own and makes alternators whine just with the power it uses so ide say it may point to an alternator issue or batteryit can still be a intermittent fault on the idle control valve as well

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battery Live Data Reading when engine switched off: 12.0v

I Started Car and ran at a normal idle and then increased to 2500 RPM

Results as follows:

Description

a). With engine running at idle (no electrics on).

idle: 13.8v 2500 RPM: 13.8v

B). Followed by switching on headlamps at full beam.

idle: 13.7v 2500 RPM: 13.7v

c). Followed by headlamps at full beam, front & rear fog lamps, air conditioning, wipers, stereo.

idle: 13.5v 2500 RPM: 13.7v

d). Followed by headlamps at full beam, front & rear fogs, air conditioning, wipers, stereo, rear heated screen.

idle: 13.0v 2500 RPM: 13.5v

e). Followed by headlamps at full beam, front & rear fogs, air conditioning, wipers, stereo, rear heated screen and front heated screen.

idle: 11.9v (Engine died but re-started ok)

2500 RPM:13.4v

they seem lower than I would expect so maybe I have a problem. Car starts okay though so could it be a problem between the feed from alterantor to battery?

[james_60]

Hi Greg

Make sure that any earth points are secure.

The Voltage seem pretty much the same (Idle vs 2500rpm)

When you did the last test with everything on did the revs dip and that is when your car stalled.

If that is correct then it sounds like 1. the battery voltage dropped low enough for the ignition to cut out 2. the alternator could not whack in enough amps to replace the used current.

Jamie

[fernsie]

See also this quote from the following thread ...

<< Link to Thread >>

one thing i noticed on my focus 1.6,

if you disconnect the connector on the alternator (will throw the battery light up on the dash) does it idle ok?

Worth checking all the earth straps maybe and that all connections are tight, as james_60 advises above and if the quote from stef123 is correct from the other thread

[greggp]

Well its been with fords today and they called me to tell me they suspect it to be an issue with the throttle body and it needs replacing......£400 they have asked for!

They say that no faults are recorded on the engine management system but that the throttle body is not reading the correct voltage!

[greggp]

Turned out to be throttle body so agreed for Fords to fit me a new one!

They wanted £400 + for it but I argued that I had raised this issue during the warranty period. They offered 50% discount which I accepted.

Drove car home last night and into work today – it’s like driving a different car,

• idles much better

• doesn’t hunt for revs anymore

• doesn’t cut out under braking

• Acceleration is a lot more responsive

When stationary it even idles a little bit higher as well which seems to have reduced the shuddering.

Keep my eye on it over the next few weeks but so far so good!