Received the charging system fault light after changing the alternator and a brand new battery... any suggestions?

 

Yes get it checked out at the dealer.
Do you have a warranty?
Can you DIY if not?
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The vehicle is not under warranty

 

Sorry to hear that. Lets see if we can narrow it down?

Was the alternator replaced with a Jaguar or aftermarket one?
We have seen and I can't explain why but aftermarket alternators have caused troubles even when operating properly.
I have come to the conclusion that getting your factory unit rebuilt is the best way to go if possible.

Can you make some voltage measurements and report back?
We need resting voltage after the car has sat all night.
Voltage when the car is running. Check it as soon as the car starts and then check it again after the car has run 10-15 minutes.

Is everything else working OK?
Car starts fine?
Headlights bright?

Since you have a error light do you have any codes?
If so clear all codes and makes sure they repeat before doing anything else.

These types of problems can be tricky to track down.

Finally what was the initial problem that caused you to replace the battery and alternator?
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Thank you for your response. I receive the charging system fault light when I start the vehicle. Once I start moving the battery light and the red exclamation point stays on. The alternator was aftermarket. The only thing right now that is wrong are the warning lights and the passenger side window not going up after I press the button in the drivers door. I will get the specs and report back ,

I'm still new to this so where will I find the error codes?

The reason why I replaced the battery and alternator is because the battery would not hold a charge and eventually would not start.

 

But there was no warning message with the old alternator? I think the new one is faulty, the old one was fine, and the problem was the battery.

No idea why you would change both at the same time, unless you need to get rid of some money.

Put the original alternator back in.

 

Go to any parts store and asked to get the codes read. Be sure and have them erase anything they find.
Just get the number of the code. Don't worry about what they think is the problem.
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have a look at the thin wire coming from the positive battery terminal will likely be burnt. cut it back add a length of wire and a ring terminal and job done

 

I am having the same problem with my XJS. Replaced Alternator after smoke and low voltage on start. Replaced Alternator and full voltage on dash volt meter. Red light on battery and no charge on battery. Suspect wire from alternator to starter to battery. still working on problem. Best way to find electrical problem is in an easy chair, a drink, and the schematic

 

The X351 needs an AGM battery and matching alternator with an AGM charging profile. If your new battery isn't AGM, or your new aftermarket alternator isn't correct, you'll have problems. Even if both are AGM-correct, a new battery might not be fully charged when it's installed. It may have been sitting on the retailer's shelf for months without being charged. You may need to put that new battery on a battery charger (not a maintainer or trickle charger) overnight to bring it up to a full charge. Short trips might not be enough for the alternator to bring the battery up to a full charge.

 

Who determined that you needed a new battery and alternator? Who selected and bought the parts and installed them? Was the Battery Monitoring Module reset?

Do you have the Owner's Handbook?

Read this entire thread, particularly about the Battery Monitoring Module.
https://www.jaguarforums.com/forum/x...warning-66265/