Possible Alternator fault???

Morning all
I have a 2007 Disco 3 Metropolis and she has been running awesome for some time now.
A couple of months back I had the battery light come on so replaced the Alternator and the light immediately but I think Im not out of the woods yet.
The issue I have now and happened nearly straight away after replacing it..……..from cold start, the engine flickers on the RPM for approx. 10 secs or so (up and down) and the radios volume also flickers during this time. After around 10 seconds, everything calms down.
Ive been back to the supplier and tried another Alternator, but its doing the same.

Could it be due to it being a non Denso alternator?

Cheers
Steve

Sorry, forgot to say, the centre display (sat nav, 4x4 screen) also flickers like mad and eventually turns off to a blank screen, but then reboots and performs as it should

I think you need to change the battery... measure voltage before the cold start

Good morning...……...

well from cold, the battery is registering 12.2v , then rises to 15.3v after approx. 20 seconds...…….

That battery is on it's way out IMO... it should have at least 12.6V in the morning, at 12.2 means that it kept only at 60% of the charge

+1^^^ but try to get voltage measurement with battery disconnected and after a few hours at rest.

Anything but a Denso alt has been known to cause issues.

Genuine Metropolis? I ask as I thought they were only available in 2006.

Good morning...….

So, Battery disconnected and left for 3 hrs...…….12.7v

And yes, genuine Metropolis, Reg Feb 2007

rac060804 said:

So, Battery disconnected and left for 3 hrs...…….12.7v

Click to expand...

Hi, i dont see the relevance of that at all... unless you want to use your vehicle with battery disconnected

Its was 12.1 when I lifted the bonnet, then 12.7 when I disconnected and returned later...……...

As for doing it, only trying things that are recommended ;-)

I saw it was recommended but i dont see the utility of that test, a disconnected battery can hold charge for long even if it's weak... that chart i posted shows how a battery behaves under minimal load like let's say a locked vehicle so as long as it looses 40% of it's charge over night on the vehicle i means it's on the way out... a good battery would get there after many days connected

btw what type and how old is your battery ?

Hi, Im not sure and will check when Im home tonight...……...Ive had her nearly a year now and has never had these electrical issues until the Alternator was changed, hence me thinking is it because its a non Denso alternator?

So you dont know how old the battery is ?

I have always checked suspect batteries off the car and left standing for 24 houes, if connected they are under draw at pretty much all times.

I would still suspect your alt.
If you think logically, it was fine before the the alt died, and has not been right since.

Google Disco3/4 forum and search on there for alt issues, loads of peope have fitted non denso, and all appear to have had issues, mosly straight away, like yourself.
I know they are bloody expensive, but it is one of them things where it is money well spent.

Metropolis are a great car, in fact the only Land Rover I have ever owned where I have not modded it at all.

Its a lovely car, drives brilliantly, but this electrical issue is annoying me...……...

Morning All.
Ok, so at the weekend I've fitted a Denso alternator, and at the moment all is back to normal, ;-)