Hi, my alternator died a few weeks ago, noticed a whining from it and battery light randomly was flickering on and off but other than that had no other symptoms

Had it replaced by a local garage (not OEM ford) for a off the shelf one, everything seemed fine but still had battery light flickering on and off, so had battery tested and it was almost dead, got that replaced for a Bosch silver one & the battery light stopped coming on, car starts and drives fine but now the headlights flicker bright and dim constantly while driving.

The interior lights flicker randomly and also when you turn the air fans on on every setting they struggle you can hear them constantly trying to ramp up but die down then try again randomly.

All this happens while you are in gear driving only, take the car out of gear and it's absolutely fine, lights go back to normal brightness and fans blow as they should, back in head and immediately they struggle and all lights flicker.

Dash board lights are absolutely fine and so is the radio etc

Guys at the garage said they tested the alternator and it was happily putting out 14.5v.

There going to come look at the car and check the grounds and the battery / alternator connections after the new year.

Any other ideas what could cause it while driving only?

Cheers for any possible help or advice where to look next

Sounds like the voltage regulator on the alternator, or the alternator is not strong enough. Did you get a replacement alternator that had the same spec as the factory one (amps output, pulley size ect)

Hi, they said they inputted the reg on the system and chose from what came up as matching one that matched the 105a that the original ford was labelled as.

I'm tempted to just get a cheap used £20 ford one from eBay and ask them to fit that and see if it solves it.

This is a problem that often affects older model Focus. Have a read of this old thread:

On 3/17/2010 at 6:48 PM, artscot79 said:

since so many ford oners have an issue with the lights flickering and interior lights etc ive been doing some searching and heres what i found.

the problem is well known to ford and the cause is that there is a high resistance in the battery wiring harness from the central junction box under the bonnet to the b+terminal of the alternator the high resistance from the 7.5amp fuse causes the alternator to pulse and this causes the flickering of the lights both insisde and out and on the dash fords technical service bulletin recommends an additional wire should be installed which takes a new feed direct from the main battery cable on the back of the alternator the bulletin number was TSB 053/2001 Part number for this cable - 1133503 from what i can gather people who have done it themselves say that you should unplug the multiplug from the alternator and pull it up to the top of the engine, splice into the red wire, then solder the new wire on and wrap it up in tape. Then drop it back down and put the ring connector on 'under' the thick red cable connector and reconnect the plug The multiplug is on the alternator, just around the side from where the thick red cable mounts.

The instructions say that the wire should be soldered on about 10cm from the plug, so you'll need at least a bit more than that.

this flickering has been blamed on alternators etc etc so as i said to many before it is common for the ford lights to flicker and this applies to all models basically its up to the person wether or not they do it yet ford never issued a recall just a technical service bulletin stating that should a customer show concern then they were to advise of this new wire otherwise say nothing.

 

Following this thread.