Fiesta ST Forums banner
1 - 20 of 21 Posts

·
Registered
Joined
·
2,688 Posts
Discussion Starter · #1 ·
My alternator is on its way out, it's starting to struggle with high demand charging. Was never an issue when my heated windscreen didn't work but now it does I'm getting the usual dimming when dipped headlights are on. Had my meter on it today and it's pushing out 12.9-13.1v instead of the usual 14.4v. Now my question is, has anyone fitted a slightly higher amp model to there mk6 instead of the higher 105a Oem model? Links as usual would be great if you have them.
 

·
Registered
2005 mk6 Fiesta ST
Joined
·
2,362 Posts
What were the symptoms of a failing alternator?
Mine has been stood a while for Covid reasons. Today stated making a whining noise from the belt area when I started it up to go for a run, a few minutes later I had an ABS light, battery light, indicators fast flashing and the windscreen wipers only running very slowly, then finally got an engine fault warning so decided to park it back up on the drive! I think there is a drip from the scuttle that lands on the alternator which probably doesn't help.
 

·
Registered
Joined
·
2,688 Posts
Discussion Starter · #5 ·
It's still going if I'm honest, I fitted a few extra earth straps between the engine/frame/battery and it didn't change anything. Nothing has changed with the symptoms and still struggling when under high load, I just can't be bothered to get under the car and change it

Your battery sounds like it needs to be conditioned, mine hated being sat on the drive for a few weeks.
 

·
Registered
2005 mk6 Fiesta ST
Joined
·
2,362 Posts
I'm not sure whether it's the battery or alternator, my gut is alternator as it started fine but was making a noise from the pulley and then went funny after about 10 minutes idling. If it was the battery I would think itd have trouble starting after 3 months standing (I know I shouldn't leave it that long!!) Or perhaps if the battery is toast then its putting load on the alternator and making it whine. Hard to know! Perhaps a multimeter will tell me something
 

·
Registered
Joined
·
278 Posts
Started to get a whine, when in the higher revs. I know gearbox diff whine, but this was different.

Didn't think much of it, was driving around alot so all was good after a bit.

Then at some standstill traffic, dash cam just reset's and then RED battery light on the dash.
Was able to hook up the device to the car and a phone app, only 11.2v when driving.

Had to drive from East to West London, just stored my battery charger in Kent. As that would have been a get me out of jail card to have another drive somewhere and also keep the car locked and alarmed.

Hopefully sourcing a spare one ASAP, and getting my Pal to fit it.. I believe with the Milltek 4-1 manifold it's a bit easier to move it out etc, it would be a good time to route the fuse wiring under the engine mount as I want to try and install a duratec cover!

It lasted for 152k miles, it had done VERY well!
 

·
Registered
2005 mk6 Fiesta ST
Joined
·
2,362 Posts
Had to do mine last year but got a used OEM one from a breakers. OEM are made by Visteon, as you say they last well and I got 120k out of mine, so I figured a used original would be worth a shot.

Yes, easier with aftermarket manifold I'd say. I think I removed the plastic shroud first in situ to give a bit more wiggle room although it was rather fiddly
 

·
Registered
Joined
·
278 Posts
So get a Lucas good looking alt, and then it works.. all good.. but then the battery does one and is not holding charge... Then get a new battery, now the alt is not working!!! Fuse, wiring, cables??? Sitting in my car thinking.. I just got my LSD gearbox fitted and my car is still not happy.. priorities
 

·
Registered
Joined
·
5 Posts
Had mine replaced last week at a garage. Very expensive job (£450). If you can find a way to do it yourself you'll be saving a lot of money, I was charged 3 hours labour and over £100 for the Alternator.
For reference my fiesta has done 80,009 miles.
 

·
Registered
2005 mk6 Fiesta ST
Joined
·
2,362 Posts
It definitely took me a good few hours to do on the drive purely due to the lack of access.
The aftermarket ones are a lot cheaper than a new OEM (Visteon), however some of the reviews on long term reliability don't inspire confidence in them.
 

·
Registered
Joined
·
278 Posts
3hours labour! 😂

First one was over charging ford alt.

Jack up, cover off, belt off, torque off, unplug and unbolt and refit and plug up.

Second one, looked new as can be.

Jack up, cover off, belt off, Tensioner off, crank sensor off, alt out, alt in things back on.

Worked perfect, battery has had a hard life*! Got mot and gearbox done. Got back into the car and battery light stayed on when I turned it on, went to try see the voltage via the in car menu, died on restart.. walked Halfords and Uber'd back - new battery £99 - car started but only worked on battery no alt, when was Charging fine when I left it with them and it had no light, thought problem solved.. then battery thought battery, but seems the alt is no good as it's only sending 10.8v, but getting power, the big fuse is okay. So somehow either a ground was not done right, or pcm, smart chrage system etc.. it's a tricky thing to fix. Gave it back to them today, saying guys the car was fine when I gave it to you. It seems the light comes on ,15/20secs after start.
 

·
Registered
Joined
·
278 Posts
So like 6 months later.. again getting my gearbox refitted after being sealed and finding out what the internals were actually.

I see the wipers are slow, thinking it's been off the road for 3 weeks, needs a run. Driving through the country lanes in Essex loving life, I see hyper flash when taking around about then, abs, then battery, engine fault, handbrake lights, misfiring. Pull over in a safe place. Check the battery it's 9/10v. Bump in reverse and running 6v odd.

So stereo/sub has killed battery and this killed alt.

Really thinking ditch the undersest sub, nothing but draining my battery and the headunit messing with my dials.

So another battery and alt purchased, let's hope it's a problem I never have to visit unless the loom has packed up as well.
 

·
Premium Member
2005, MK6 ST150 (pre face lift )
Joined
·
1,213 Posts
So like 6 months later.. again getting my gearbox refitted after being sealed and finding out what the internals were actually.

I see the wipers are slow, thinking it's been off the road for 3 weeks, needs a run. Driving through the country lanes in Essex loving life, I see hyper flash when taking around about then, abs, then battery, engine fault, handbrake lights, misfiring. Pull over in a safe place. Check the battery it's 9/10v. Bump in reverse and running 6v odd.

So stereo/sub has killed battery and this killed alt.

Really thinking ditch the undersest sub, nothing but draining my battery and the headunit messing with my dials.

So another battery and alt purchased, let's hope it's a problem I never have to visit unless the loom has packed up as well.
Hi blk-yell
I can't see how your battery would kill the alternator
Have you checked the alternator output ? ( charging between 14.2 & 14.7 volts ) - If its over this it suggests the alternator regulator is shot and as I think you got a new alternator - give it back under warranty.
I'm thinking that when you put the ignition key into position 1 you get a battery light on the dash, as without this the alternator won't charge ( I think its called an exciter circuit)
Have you done a load test ? - Turn everything on in the car - rev to 2k, you should get 13v at the battery.
If you have concerns about your sub, turn everything in the car off - disconnect the negative battery lead and put an amp meter in series between the lead and the battery terminal, you should get pretty much 0 amps, ie nothing is drawing power.
If you are finding something is drawing power when the car is off, start pulling fuses and rechecking until u identify which circuit the amp drawer is on.
Hope this helps
Al
 

·
Registered
Joined
·
278 Posts
Thanks Alan for writing that, the alt gave a AC reading, getting replaced now. Yeah will have to test the drain, thought we solved it with nee headunit and iso but no. Obviously didn't check our work hence problems. Will know more in a hour.

I power the headunit and sub, guess I need a professional to fix it with their knowledge.
 
1 - 20 of 21 Posts
Top