XF Red Battery Warning Light

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Nov 27, 2018 | 12:39 PM

Dean1

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Joined: Nov 2018

Posts: 2

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From: Glasgow

XF Red Battery Warning Light

I turned my car on to the red battery warning light (of death) on Sunday. Image shown. The car still drove on Sunday and I could clear the message from the dash but didn’t bother. Wipers were slower than usual.

I went back to it today today and it won’t start. I managed to get into Engineering Test mode. I managed to gather information on what appears to be the battery voltage.

Can someone explain what all this means as I have no real clue and a car that is sitting outside not going anywhere.

Thanks.

Nov 27, 2018 | 12:43 PM

Dean1

Thread Starter

Junior Member

Joined: Nov 2018

Posts: 2

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From: Glasgow

Don’t know why the images won’t attach. We can all google the big red battery I’m sure. Data from battery info in engineering test as follows:

Battery Volts
Local: 11.25
Vehicle: 11.00
Raw: 1109
A/D: 568

Nov 28, 2018 | 09:41 AM

Bigg Will

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Joined: Nov 2014

Posts: 1,592

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From: SO, CaLi

Quote:

Originally Posted by Dean1

Well anything under 12 volts = a dead battery, but because you got the charging fault (Red batt light) first and have slow accessories I'd be willing to bet your Alternator has bit the dust. Know that the battery powers the car, and the alternator charges the battery, so your battery needs to have a good charge not only to test it, but also test the alternator. And yes the alt can run the car without the battery, but is not meant to do so as alternators don't like lots of transient loading which the battery is perfect for.
Options?
Charge the battery, start the car and test the alternators output.
Bad alt options
New one from Jag..$$$$$
New on from parts store $$$$ and suspect quality. Might fit in easy, might not.
Have yours rebuilt $$$, This is what I did, even getting mine rebuilt up to 250 amps from the stock 150 amps only cost $300, and you know it will fit back in easy.
My thread on it
https://www.jaguarforums.com/forum/x...change-189069/