Disco 2 TD5 Battery Light

0writer · Dec 19, 2015

Evening,

The battery light came on the TD5 this week. I tested the voltage and it appeared to be the alternator not charging. I had a spare new battery so replaced the one in the disco anyways. Called the garage, explained what I had done so far and let them at it. Their diagnosis was alternator and they replaced it.

Car came back Friday with no problems at all. Went out this morning and the battery light has come on again. I've not done any further testing but considering it has a new battery and alternator, apart from the garage possibly not tightening all the cables properly, could there be any other cause?

Would like to try and self-diagnose rather than have to lose the car in the bloody garage again.

Thanks

freelanderoig · Dec 19, 2015

bad earthing some where ????

johnlad · Dec 19, 2015

You paid the garage to fix it so give it back to them

freelanderoig · Dec 19, 2015

can be lot of inconvenience ..getting car there..getting to work ..back to the garage,,i know..lol..sun tomoz..few hrs checking a few things wont harm and if it is bad earths ..easy fix..new batt an alternator in winter not bad idea ....he wont get car in few days anyway prob..

discool · Dec 19, 2015

It's so easy to have checked that the alternator is charging before involving a garage, perhaps you should have done self-diagnostic before visiting the garage.
So... it's not unknown for a referbished alternator to be faulty and it can also still happen with a brand new one, therefore with your multimeter check your alternators voltage output first.

Thomo1927 · Dec 20, 2015

Not sure if it's the same as a Disco 1,On the back of the alternator there are a couple of thin wires .Mine snapped a while back and the battery light stayed on ,Simple case of stripping the wire back and fitting a new spade connector to it.

sierrafery · Dec 20, 2015

The ''battery" light on a D2 has nothing to do with the battery, it's just the icon which can induce that ideea, it's exclusively for alternator output but not on the same circuit with the power feed to battery so it's possible to have normal charging voltage to the battery and the warning to come on, if the charging is good(around 14V at idle) and the warning still comes on the problem is on the warning lamp's circuit cos it must get above 7.6 V on the earth path from the alternator on a dedicated path which goes through two connectors and a header(despite of the description of instruments in RAVE where they say wrongly that it's hardwired), if you have RAVE i'll tell you where to check.

0writer · Dec 20, 2015

Thanks for the replies (even if some of you didn't read my original post properly before posting a grumpy reply). For the helpful ones, especially sierrafery, thanks. I tested the output this morning and was getting a steady 14V with the engine running and 12.6V with it not. Took it back to the garage and have left it with them. One thing I did notice is that when the revs are high, the battery light goes out. I'll let you know the outcome.

freelanderoig · Dec 20, 2015

0writer said:
Thanks for the replies (even if some of you didn't read my original post properly before posting a grumpy reply). For the helpful ones, especially sierrafery, thanks. I tested the output this morning and was getting a steady 14V with the engine running and 12.6V with it not. Took it back to the garage and have left it with them. One thing I did notice is that when the revs are high, the battery light goes out. I'll let you know the outcome.

both out puts seem ok..sure theyll sort it ..let us now please

discool · Dec 20, 2015

As an qualified engineer when someone carries out an electrical test on a component or circuit and their response is "appeared" or sometime seems, it leaves me with some doubt about their abilities with electrical systems.

If my techies were to say something similar they would be on a warning, but as they know what they are doing, functioning and testing ok, or not testing ok replacement required or something similar is what I can expect to see in their report.

Dan_Trials · Dec 20, 2015

discool said:
As an qualified engineer when someone carries out an electrical test on a component or circuit and their response is "appeared" or sometime seems, it leaves me with some doubt about their abilities with electrical systems.

If my techies were to say something similar they would be on a warning, but as they know what they are doing, functioning and testing ok, or not testing ok replacement required or something similar is what I can expect to see in their report.

This is an approach I use when some one tells me they took their vehicle to a garage and they checked X, Y, and Z and it was probably part A or part B so they replaced part A because it was easier/quicker/cheaper and the problem is still there so it's probably part B but that's more expense and they can't be sure it will fix it, so now they want me to look at it because they don't want to waste more money at the garage.
1. What reasoning did they use for testing X, Y, and Z. What methods did they use and how did they select those as the best methods. How did their findings compare to the specifications for those components at those test points.
2. What facts and figures do they have to say with 100% certainty that part A should be replaced and part B is suspect.
3. How did they test part A to confirm it should be replaced.
4. What tests did they perform after replacement to show what, if any, differences it made.
Usually this is met "umm, well, err....." at which point I laugh and then say "ok, lets fix it properly".

discool · Dec 20, 2015

Now that ^^^ sounds like 'brain damage' I hope you charge....

freelanderoig · Dec 20, 2015

discool said:
As an qualified engineer when someone carries out an electrical test on a component or circuit and their response is "appeared" or sometime seems, it leaves me with some doubt about their abilities with electrical systems.

If my techies were to say something similar they would be on a warning, but as they know what they are doing, functioning and testing ok, or not testing ok replacement required or something similar is what I can expect to see in their report.

diff is were not...qualified engineers...just every day folk with limited experience , i was a mechanic and albeit 20y ago but a simple test was put every light , switch and power consuming item on we could and see what the alternator output was, which was how it was done.
so please note..were not one off you techies, you wont be giving any warnings out, try not to be so arrogant towards a group of every day folk trying to help a fellow member/ ..pity on your techies...lol ,

jamesmartin · Dec 20, 2015

Dan_Trials said:
This is an approach I use when some one tells me they took their vehicle to a garage and they checked X, Y, and Z and it was probably part A or part B so they replaced part A because it was easier/quicker/cheaper and the problem is still there so it's probably part B but that's more expense and they can't be sure it will fix it, so now they want me to look at it because they don't want to waste more money at the garage.
1. What reasoning did they use for testing X, Y, and Z. What methods did they use and how did they select those as the best methods. How did their findings compare to the specifications for those components at those test points.
2. What facts and figures do they have to say with 100% certainty that part A should be replaced and part B is suspect.
3. How did they test part A to confirm it should be replaced.
4. What tests did they perform after replacement to show what, if any, differences it made.
Usually this is met "umm, well, err....." at which point I laugh and then say "ok, lets fix it properly".

sometimes it is just guesswork as theres no way of isolating a problem,though charging or not is easy enough to test

freelanderoig · Dec 20, 2015

i think most self maintaining car owners do there best but have limited knowledge enhanced by experience, i do have a good grounding as an ex mechanic but landrovers are new to me in that they always went to specialists for repair, but as an ex mechanic when trying to help the ordinary home mechanic
i always try to explain in simple terms ...and you simple can not expect to find/solve every prob as a self maintainer

discool · Dec 20, 2015

freelanderoig said:
diff is were not...qualified engineers...just every day folk with limited experience , i was a mechanic and albeit 20y ago but a simple test was put every light , switch and power consuming item on we could and see what the alternator output was, which was how it was done.
so please note..were not one off you techies, you wont be giving any warnings out, try not to be so arrogant towards a group of every day folk trying to help a fellow member/ ..pity on your techies...lol ,

I see you have only been on the Forum for 7 days but already have 124 posts that must be a record, have any of them been useful to others with you experience of 20 years ago with mechanical issues, although as u are 'just every day folk with limited experience" .

A difference of opinion is the spice of life.. Enough said hope u agree

Disco 2 TD5 Battery Light

0writer

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freelanderoig

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johnlad

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freelanderoig

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discool

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Thomo1927

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sierrafery

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0writer

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freelanderoig

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discool

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Dan_Trials

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discool

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freelanderoig

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jamesmartin

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freelanderoig

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discool

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