Member Since: 07 May 2018
Location: broome
Posts: 64
Red Battery warning light. Conflicting research.
Hi,
2007 tdv6. Has had the weird suspension warning and dropping while driving intermittent. Has gone away for a while but the disco does lower over night. I think front right is culprit.
I digress from issue but wanted to give history.
The red battery warning light came on with the p066 ish code for the field generator on nanocom.
Logic states that alternator is diddled.
However, volt meter shows it kicking about 13.5 v whe running and at time of checking the battery it was 12.4.
Reset codes and now the battery light seems to come on when car starts but goes away shortly after. So ignoring the fault code, battery would make more sense?
Battery has 2019 written on it so quite old though no issues until now. Owned the car 3 months or so.
I was about to get a traxide system for it but want to ensure all is good before I do....
Thoughts and crackpot theories welcome.
Live in brisbane, which has been hot and very wet recently.
Cheers 🍻
31st Mar 2022 5:59 am
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2462
Depending on the state of charge of your battery 13.5v is low for the engine running these vehicles quite often put out 15v when first started although the voltage will drop back down as the battery charges.
There is quite high demands on the electrical systems of these cars so if it was my vehicle i would change the alternator just to be on the safe side.Andrew
D3 2.7tdv6 2005
D4 3.0 SDV6 Commercial died and gone to LR heaven
D5 3.0 SDV6 HSE
31st Mar 2022 6:28 am
viagression
Member Since: 07 May 2018
Location: broome
Posts: 64
Thanks for response.
Side question, is there any thing wrong with not getting a denso alternator as they are a fair bit more expensive.
31st Mar 2022 6:38 am
garrycol
Member Since: 06 Dec 2010
Location: Canberra
Posts: 1117
aja4x4 wrote:
Depending on the state of charge of your battery 13.5v is low for the engine running
Sorry not agreed - with a battery in good condition and with the engine running well after start 13.5v is about normal. Certainly on start, voltage will be up just over 14v but this is only to top up the battery from the engine start and quickly lowers back to around 13.5 after a little a while.
As far as getting a Denso - yes if you can, shop around they range from around $600 to well over $1200.
When my alternator failed back in early 2018 I needed to get a new one quick and rang Ashdown-Ingram who assured me they had three in stock. Yes when I arrived they had three Denso types in stock but not Denso brand. The ones they had were OEX brand and are basically the same as the Denso - OEX are a quality parts manufacturer from Taiwan and I have used their stuff before.
I fitted the OEX the next day and after 4 years and nearly 100,000km it is still running fine. OEX pricing is the same range as the original Denso.
Yes I would always try to get an original Denso but I would not die in a ditch if an alternative quality brand was available.
31st Mar 2022 6:45 am
viagression
Member Since: 07 May 2018
Location: broome
Posts: 64
Great info thanks.
So the 13.5 measurement was made after a 6km trip and shut down.
This trip is when the battery light came on.
I measured the battery at 12.4 ish,
Started and then measured alternator at 13.5 steady.
I will do some more checks.
For my limited knowledge the fault code is not in line with the voltages and behaviour so want to best guess.
It's my partners d3 and I have one also, so I could swap the batteries but worried I will end up with two cooked batteries and a duff alternator.
Just checked few hours after a good run and battery steady at 12.32v
Which is low.
31st Mar 2022 7:09 am
rrhool
Member Since: 28 Aug 2014
Location: Norfolk
Posts: 4445
viagression wrote:
Thanks for response.
Side question, is there any thing wrong with not getting a denso alternator as they are a fair bit more expensive.
Only ever get a genuine Denso alternator! Anything else will give you never ending troubles and fault codes! Be warned Richard
D3 SE 2007. Triumph 2.5Pi 1973. Ferguson TEA20 1948.
Discovery 2 4.0 ES 2001- Gone
Discovery 1 300Tdi ES '95 - Gone
Range Rover Classic '79 - Gone
31st Mar 2022 8:06 am
Naki Blake
Member Since: 31 Dec 2021
Location: Taranaki
Posts: 258
Somewhere on this forum someone has posted a table which shows as the ambient temperature increases the charging voltage decreases. I can't however find it again.
On my Disco 3, the charging voltage sits at about 13.8v at say 18oC outside. If I'm driving in hot weather say 25oC to 30oC, and I'm driving around the city, lots of idling at lights, the charging voltage drops back to about 13.5v
1st Apr 2022 4:24 am
viagression
Member Since: 07 May 2018
Location: broome
Posts: 64
Well the heat would then explain the "low" alternator charge.
Think I will transpose batteries this weekend.
1st Apr 2022 5:13 am
M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8154
Have you checked the earth lead?-a poor earth could cause the symptoms you are having, body to engine earth is a common fault.It can when others can't,
It will when others won't,
It goes where others don't.
1st Apr 2022 1:19 pm
viagression
Member Since: 07 May 2018
Location: broome
Posts: 64
Not had 2 minutes.
It's driving fine.
Light comes on just after start, goes off few minutes later.
Will give it a going over this weekend and check the earth's then will transpose batteries.
Thanks team.
1st Apr 2022 1:34 pm
lynalldiscovery
Member Since: 22 Dec 2009
Location: Maidstone
Posts: 7274
My alt runs at a steady 15.1 volts pretty much all the time, I only do a short commute so the thing is trying its hardest to play catch up.
Even on a long run it is not often it drops below 14v.
1st Apr 2022 8:31 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4871
13.5v is below minimum operating voltage and it should be a tad higher than this when the engine is warmed up.
Typically 13.7/9v is what you want to see as a minimum safe value. When cold the value usually starts out around 14.7/9v but it can go above this depending on load, battery state, and ambient conditions. yµ (idµ - eAµ) ψ=mψ
1st Apr 2022 8:44 pm
Naki Blake
Member Since: 31 Dec 2021
Location: Taranaki
Posts: 258
Is the charging voltage controlled by the ECM?
If that's the case, can the ECM charging voltage be adjusted using a GAP IID tool? Is there anything in the CCF to alter charging voltage? As mine is a little on the low side, can it be tweaked up?
Thanks
Blake
2nd Apr 2022 3:26 am
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10485
Also note there is a significant delay between the voltage falling or rising and the light changing status.
Maybe 1 minute
2nd Apr 2022 10:41 am
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4871
Naki Blake wrote:
Is the charging voltage controlled by the ECM?
If that's the case, can the ECM charging voltage be adjusted using a GAP IID tool? Is there anything in the CCF to alter charging voltage? As mine is a little on the low side, can it be tweaked up?
Thanks
Blake
No you can't influence the behaviour of the charging system as it's control parameters are not accessible via diagnostics. Management of the alternator is shared by a number of components, engine ECU/EMS, ATCM, and the alternator itself. Load management is handled by the ATCM software.
A cold battery is less responsive to accepting charge from the alternator. Temp is measured by the various engine a body sensors so that a battery temp value can be established. This is why you see the higher alternator output on a cold start up. As the engine and everything else begins to warm up the voltage is set back to a level which will not cause the battery to boil, but will meet the demands placed on it by the driver.yµ (idµ - eAµ) ψ=mψ
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