This alternator is the exact same as my original according to the label.

Merriam also assured me it is brand new.

I am going to drive the car for a while and then check using SDD. I am kinda hoping after a while an error code will be thrown that will give me an idea.

My iCarsoft i930 showed zippo.

 

Would guess that's the best thing to do. Wonder if the cold weather has a factor in the equation? All battery's have to work a lot harder in the winter to start the motor. The voltage when first cranked may be a touch low for all systems to be fully supplied with enough juice to satisfy them and clear the light. Just a thought, wonder if you took it to someone with a dealer level scanner,if that would shut it off? When one goes to them to fix the red light, and are told they need a new battery, the light needs to be out when the customer leaves the dealer, or back it will come.

 

Maybe cold weather has something to do with it.

I am toying with the idea of running jumper cables from my 2013 Range Rover to the Jag.

The alternator on the RR puts out just over 15 volts when started initially.

I dont think I can do any damage trying this.

My JLR SDD software does have a battery routine so will try that again.

 

Read this first. I know Mercedes and Jaguar warn against it:
https://www.mynrma.com.au/cars-and-d...ot-a-good-idea

 

mynrma doesn't give explanations, seems to me only a warning to attract consumers...
Actually I would be surprised that jumpstarting a vehicle (with an autonomous jumpstart system) would do damage if you do it properly: i.e. by linking the negative post of the jumpstart system to the ground of the car (not to its negative post, to avoid overvoltages if grounding to the car is defective).
Jumpstarting with the engine running of another vehicle may be more tricky, I would avoid it.
But the usual autonomous jumpstart systems are nothing else than a battery!
Btw, there are now small Li-based jumpstarters that you can keep in your trunk and that are very useful.

 

The small Li-based jumpstarters I carry in all vehicles including the boat!

Ok I will not risk connecting the RR by jump cables.

 

Did you read the article?

They quoted auto makers:
“The big change from then to now is computers and it’s not as if a modern car has just one – a Mercedes-Benz S-Class from a few years ago has 64 ECUs (Electronic Control Units),” he said. “Hooking up jumper leads can zap these computers.

“Jaguar warned us that you could damage the whole wiring harness if you try to jumpstart one of their cars, and that warning is probably applicable to most vehicles built in the past five years.

“A five-year-old Audi was recently taken to an NRMA approved repairer with an electrical system so badly damaged by an attempted jumpstart that, in the end, it was actually cheaper to write the car off rather than repairing the damage.”

“Well-meaning car owners can do massive damage very easily,” Darrin says.

So yes Modern cars can be seriously damaged, but I fully agree with your autonomous jumps start systems. Glad you're not hooking up to the RR Jackra.

 

Yes I understand the risks.
Still do not fully understand why voltage and current from an alternator that outputs just over 15 volts would do damage.

Jaguar specs say that the alternator output can go above 15 volts when the alternator is cold.

I was not actually going to jump start anything simply connect the running alternator/battery from the RR to the running Jaguar battery +ve and a ground.

Still I am not going to risk it.

 

Yes I did read the article.
Still that does say nothing on the actual causes that may fry the computers.

Only possible cause of damage of a car's electrical system could be an overrun in voltage, either transitory or not, local or not, compared to the voltage that the usual battery would deliver.
Unless there are plenty of electronic circuits in the jumpstart box (I doubt it), I see no reasons for a transitory overvoltage on a car's system when connecting to the ground of the car: the output voltage of the jumper does not exceed 13 Volts, it's just a battery!

Of course the jumper's negative cable has to be connected to the ground of the car, not to its battery's negative post.
Otherwise there may be risks of overvoltages in some of the car's electrical systems, depending on the quality of the electrical wiring of the car (e.g. an already damaged harness) and/or on the grounding of each of these systems.
[edit: I see the recommendation of Ctek chargers to connect the negative cable preferably to the ground instead of the negative post of the battery: reason there is to avoid sparks]

Linking to the alternator of another car is more risky as additionally there might be higher voltage transitories coming from the other car's alternator.
Also there may be grounding issues between the two cars.

 

I keep jump packs in all my vehicles. Have proved very helpful from time to time for either me or fellow motorists or friends in trouble.
However I think it would not be sensible to use jump leads in the old old fashioned way of having the jumper car's engine running or being revved up
Connecting leads or jump packs and just leaving them for a few minutes without doing anything can help as this can help top up the flat battery.

 

Finally got around to running my JLR SDD software, V145, to check out the charging system. Has been way too cold up until today.

With this version 145 I pick up a P1632 DTC. Which I did not on an older version of the software.

It says it is a permanent DTC and gives a series of engine idle and 1500 rpm tests to run.

I have also read that any appreciable drop in voltage between the alternator and battery likely means a bad cable.

If I remember when I checked this a while ago I was getting a little less than 0.5 volt drop.

Is this significant enough to warrant cable replacement?

If it is I will replace it and the starter motor to alternator cable as well.

 

I think you will find the warning re jump stating really concerns a FLAT battery rather than a slightly down on volts battery.

 

This is nothing to do with a flat battery.

The ONLY reason I mentioned LINKING my RR alternator to the Jag is because it puts out a higher voltage.

I replaced the battery and have tried 4-5 different alternators. The last a genuine new Jaguar alternator specifically for MY vin of my car and still get the battery red light.

Today is the first time I read the P1632 code. An earlier version of JLR SDD did not pick it up and neither does my iCarsoft 930.

 

First, sorry. I've been calling you Jack. As a whole, .5 drop added between positive and negative side of the alternator is acceptable. I think I'm wording that poorly.

Here's an easy read on it and link to a video.
Tech Tip: Checking Voltage Drops | Delco Remy

You'd need a load tester to prove it out. I presume you followed all of the pinpoint tests in the service manual and that's what you were referring to above John?

 

Sean yes I have done some pin point tests but not all.

I will have to wait until I get back from my out of town trip before I do any more tests.

The other thing is that I have assumed that the battery is good as it is new and it is apparently fully charged plus it seems to give a good voltage across the terminals.

However a battery can give a good voltage but still not be fully effective I think?

I am grasping at straws . It cranks and starts the car easily.

John or Jack is fine.

 

In the old days, the battery red light was a simple analog circuit that, in simple terms, validated that the alternator voltage was higher than what the battery put out. If the reverse was true, then the idiot battery light would turn on indicating that the alternator was caput.

I would venture a bet that the circuit that is powering the idiot battery light is much more sophisticated than that and possibly driven by the ECM by comparing a set of various inputs. It appears that this diagnostic circuitry is at fault and not your battery/alternator/cables. I would reverse my thought process and figure out why this circuit is faulting (could be a wire break the feeds the ECM) as opposed to continue to blame battery and/or alternator.

Something to think about...

 

I agree with you Lagonia and that is the conclusion that I have come to.

It is going to be much more difficult to solve.

 

I would have to agree with Lagonia too. I was thinking of the old systems while following this. Simple tests that you have completed confirm units are working/charging. Battery volts/amps, alt output ( at alt and at battery) That's all the system is supposed to do. It all seems to be working, but the idiot light system doesn't think so. Lets get back to basics. It's just a charging system, unlike many of the other over-engineered complicated systems on our cars. I over thought my charging problems on my SV-8. Just my 2 cents.

 

It is something to do with the idiot light system of that I am pretty sure.

It will have to wait until I get back from a trip to MA. Then I will go thru the pin point tests one by one methodically.

That will be after a bit of driving around tho.

 

Well now there is the idiot light system and then there is me the idiot!

Just for good measure I checked both fuses relating to the alternator, which I have done before, and low and behold the trunk 10A fuse was blown!

Replaced it and, for now at least, the battery red light is off!!!

I swear I checked the fuses before........

Maybe got the wrong one?