So the battery red light came on yesterday with no fault codes.

Could not get an accurate voltage reading with the voltmeter I have so purchased an Exide Global Extreme L5/49x that was recommended by Box in another thread.

Got it from BJ's and even had a $15 off coupon for it.

I did however forget to take the small drain hose fitment off the old battery which was 13 years old as I think it was original.

Anyway after installing the new battery I still get the battery red light and no fault codes.

I am now thinking that I have a bad alternator which I understand is a B****
to work on.

I do use a CTEK maintainer.

 

Not terrible. You'll want one of these

http://www.harborfreight.com/1000-lb...bar-96524.html

The instruction in the manual is pretty straight forward. You need the support bar to hold the engine up while you remove the motor mount.

 

Easy enough to check the voltage at the battery at idle. You should see a code if the alternator isn't giving the correct output (P1632?). This is an interesting read on the S-Type forum.

https://www.jaguarforums.com/forum/s...-116037/page2/

Might as well ensure you have the correct battery, though I would trust Box's input. EDIT - sorry, standard lead acid battery recommended by Box. Battery should not be the problem, though contact might be. Check the voltage with the voltmeter on the outside of the terminals with the car running, then On the posts themselves.

 

Thanks Sean. I had actually read that thread in the S-Type forum beforehand.

I am getting about 12.5 volts with engine running both on the outside of the battery connectors and on the terminals. I think it is supposed to be 14.5 volts?

I get about 11 volts with engine off. I am using the 50 volt scale on my volt meter so not that easy to read down to the volt.

Also the battery is not fully charged according to my Ctek charger.

Would it be wise to replace the engine mounts while I am at it?

Also anyone recommend a good alternator?

 

Quote from Thermo a while ago in the (XK8 / XKR ( X100 ) Forum:
open up the hood and trunk of your car. Connect a multimeter across the battery posts (engine turned off). Are you getting 12.6 VDC? If no, place the battery on a charger and get it up to 12.6 VDC. If yes, leaving the multimeter connected, start the car. Does the multimeter jump up to a voltage above 13.0 VDC? If yes, then it appears your problem is with your "battery" light on the dash, write me and I will give you some more checks to do. If no, move around to under the hood of your car and locate the alternator. Coming out of the alternator will be a small wire that is a white wire with a purple stripe on it. Place the red lead from the multimeter on this wire and the black multimeter lead to chassis ground. Are you getting above 12.0 VDC on this wire? If no, then check fuse #15 in the passenger side fuse box. If this fuse is good, then you have a wiring problem between the fuse box and the alternator. If you are getting 12 VDC on the white/purple wire, then verify that you are getting great than 13.0 VDC on the main terminal leaving the alternator. If you are getting more than 13.0 VDC on the main terminal, then you have a bad wire between the alternator and the starter. If you are not getting more than 13.0 VDC, you have a bad alternator.

It is possible that the wiring at the plug for the alternator is bad and can be giving you grief. So, before you replace the alternator, make sure to inspect the plug and verify no corrosion.:

Is the above valid for my 2005 XJR?

 

I would change the mounts while I'm at it if I were King.

I would go with OEM Alternator based on that S-Type Post, even a used one.

I saw your post on the X100 also but can't help as I don't know the wiring or alternator that was used vs. the x350, but the logic appears sound and I would always check wiring and connections before swapping the alternator.

 

Sounds like a modern meter is needed. They cost from about $5.

 

Yes I have come to that conclusion!

 

Most alternator failures come from brush issues. They do wear out. You can have a local rebuilder replace the bearings and commuter slip rings and brushes, or you can seek a rebuilt or new one, or you can rebuild it yourself. You can access video that can help if you want to rebuild your own, and parts are widely accessible.

 

So installed reman alternator. Still get battery red light.

Using JLR SDD I see a "flight recorder" dtc but nothing relevant to the charging circuit or battery.

Never the less I cleared all DTCs.

I still get battery red light.

At the battery poles with ignition off I get a reading of 12.85 volts.

At idle 14.07 volts

With headlights on full beam I get 14.00 volts.

So as far as I can tell I am charging just fine. So by the look of it I will have to live with this red light.

 

You need to source a genuine Jaguar alternator (new = $$$$$, or used) or swap out the regulator from your old alternator to your reman unit (provided your alternator failure was not due to the regulator crapping out)

Those are the only two options available to get rid of the battery light on dash.

This was a known issue on the S Types (00-02) I would presume it carried over to the newer models.

 

Is there anyway of testing the regulator? I do have it off the original alternator.

 

I have only looked at Denso alternators given the fact my original was Denso.

Would a Bosch alternator be a good replacement?

 

Ok so I have found an alternator on Amazon that specifically states it replaces my alternator. It had the exact code that is on my original.

I had not seen that on any of the others.

 

What is the denso part number on the regulator from your old alternator?

 

I was mistaken about the regulator. It was just the brush holder that I have off. The regulator I have not been able to get off as I cannot see how without breaking something

However I can see on the bottom of it CS2 0081 and under those letters/numbers 7F12

 

The Denso part # will begin with something like 100211-xxx or 126000-xxx

 

On the outside of the alternator on a label that says Jaguar 12v

I have: 2W93 10309-AB

10 42 10 30 82

DENSO

 

Well I am resigned to living with the battery red light on at all times.

I see no codes at all but do believe that this alternator is charging, just like the others.

Just installed a new OEM alternator with a set point of 14.2 volts and rated at 200 amps.

The battery with ignition off reads 12.85 volts and it is fully charged per CTEK device.

At idle I read 13.89 volts which is lower than in post #10 with a reman alternator.

Under load with headlites on and fan/ heater on it drops slightly to 13.86 volts at idle.

I cleaned connectors including the engine ground connector when I installed this alternator.

I plan on running my JLR SDD software tomorrow and run the appropriate test.

I did btw get a fault and restricted performance but that is because I forgot to plug the MAF connector back in!

 

OEM from Jaguar/Ford or OEM branded alternator purchased elsewhere?