I've read lots of threads and I'm wondering if I need to replace the alternator with a Gaudin? I am getting the impression that Gaudin is what is Jaguar's original equipment was, what a dealer is going to be pushing across the counter. I replaced the alternator with a Bosch I got at NAPA because that was what was in the car and didn't know better. Overall the Bosch alternator seems to be working, it is definitely charging the battery.

But I get the message 'battery not charging', and a red light on the volt gauge.

I checked the voltage with a multimeter and I'm getting a little over 14 volts at the main alternator terminal - at the starter wire, and the small white & purple striped wire that comes off on the alternator plug. Also, I checked ALL the fuses in the car (for good measure) for continuity. The the fuses are good. The dash Volt gauge also shows 13 volts when the car's running, and that's fine.

I've been troubleshooting it and having no luck...I replaced the battery and the serpentine belt already.

These are the other things I still have to check.

- Voltage regulator - I'm thinking maybe the Bosch version isn't compatible, that's why I'm asking about the Gaudin alternator? The Bosch I have is putting out good voltage, so to me it seems to be fine. I don't know what I can check from the alternator's voltage regulator to confirm it's good. If I should be getting a Gaudin, I don't get it, but ok. I sure don't want to be swapping alternators until I find a good one.

- Voltage suppression module - I haven't been able to figure out where that's located. Is that on the firewall? All I've found online are a pdf drawing that does not look like anything I'm running across.

- Volt/clock/oil cluster - I have to figure out how to test. I found a video of how to remove the piece of dash to access the cluster. That looks easy enough to do. I don't know what I'm testing for yet.

- Grounds - They look good but need to get the multimeter on them.

- Starter cable - In a thread, if I understood it right, that if my voltages were 14+ Volts at the battery and alternator output wires, and these were good: fuses, dash volt/clock/oil cluster, that the problem could be a bad starter wire coming from the alternator.

Thanks,
Stephan

 

Stephan,

1) the original alternator was from Denso. I strongly advise you not to settle for substitute brand.

2) are you saying that you get red light and Batt not charging message, but measure 14 volts at alternator? What do you measure at positive battery terminal?

unfortunately the site keeps reverting to "mobile mode". I used to be able to select view full site and it would change and stay changed. Not anymore for some reason. Mobile mode hides your original message so I can't see what else you asked.

the comment about 14 volts is confusing. We'll help you through it.

John

 

With the car off and using your multimeter or a new, free, Harbor Freight multimeter, what does the battery voltage (in the trunk) read? Turn the lights on and now what does the battery voltage read?

If the alternator is putting out 14 volts, that is enough to charge the battery. If the battery is bad... like has a bad cell, it may not want to charge.

The voltage suppression module appears to be a capacitor to reduce radio noise and doesn't have anything to do with the charging system. On my '97 it was under the airbox.

 

John

1) I'll order a Denso so I have it and if all else fails swap it out. I will get it from a site specializing in Jaguar. I sure don't want anymore "substitute brand" experiences. That's great...Won't need to spend $756 for the Gaudin alternator.

2) These are the voltages I'm getting at the battery, with the multimeter red probe on the + terminal, and black probe on the - terminal.

Lights off Lights on Dash Volt gauge
Engine off: 12.16 12.01 n/a
Engine on: 14.16 14.14 13.0


Stephan

 

Lower than 12.5 and the battery is not charged. It could be the battery is not fully charged by the alternator, or the battery is going bad.


Charge the battery overnight with a 2 amp charger and test the voltage again. if it isn't over 12.5, start looking for a new battery.


If it is over 12.5, your alternator is likely intermittent.

 

12.16 is not a healthy battery. Put it on a charger overnight and it should maintain at least 12.5 after a few hours rest. But I don't think that's the reason for the message and light.

I recall a thread dealing with this, but not the outcome and I have to be elsewhere so I can't search right now. Have you tried a forum search for battery not charging?

 

Ungun,

These are the voltages I'm getting at the battery, with the multimeter red probe on the + terminal, and black probe on the - terminal.

Lights off / Lights on / Dash Volt gauge
Engine off: 12.16 / 12.01 / n/a
Engine on: 14.16 / 14.14 / 13.0

On 8/2016, the car needed a new fuel pump and brought it in, and replaced the battery with an Interstate brand. The shop I brought it to couldn't figure out why the car was sending the "battery not charging" and the dash red light was on, and confirmed the battery was good. I really took the car to them for a new fuel pump, not the battery, I just wanted them to put new battery in to see if that would fix it

Stephan

 

RJ

I'll put it on the charger tonight and see where it gets. I don't remember it ever being over 12.25. It's a relatively new battery (8/2016) and should still be under warranty.

Stephan

 

The proper battery for these is an AGM, just like are used with back up power supplies, solar power battery banks or kid's ride on toys.


AGM batteries state of charge is easy to determine by the voltage (liquid acid batteries are much tougher).


There are lots of tables online that show the state of charge vs. voltage:



If the battery is less than 12.5, it isn't being fully charged.

 

RJ,

I bet I've read all the threads out there a few times but it's sure worth another look. I've been using them to trouble shoot this. I thought I had the battery and alternator checked off, but maybe I need to replace both. What are the odds of that?

Stephan

 

Great information...Hope that's it, batteries are easier to change than alternators. I'll trying charging it overnight, see what it gets to, and I can use this if I have to talk to the shop I got it from.

 

Stephan, I paid $225 for the Denso alternator after I finally gave up on my 3rd AutoZone alternator. Prices varied up to $725, that high one from a local garage , no install charges included.

hope this helps you find a good deal.

John

 

Thanks John,

Yeah I'm staying away from Autozones, Advanced Auto and NAPA, it hasn't worked out very well for me either. Denso it is!

Stephan

 

Ungn,

After putting on a 2 amp charger all day it the voltage was 13.48.

After reconnecting the battery +/- cables it got down to 13.11, and with the lights on it was 13.0.

I ran the car and the not charging message and red were still there. I let the car run for 15 minutes. After shutting the car the battery was at 13.14.

 

That sound like the alternator. A bad battery wouldn't go to full charge like that, but your alternator doesn't seem to be bringing the good battery back up to full charge.

13.0 volts under a load indicates the battery is in good shape.

 

I wanted to send a followup on the alternator problem I was having. I replaced the Bosch alternator I had originally installed (got it from NAPA), with a Denso alternator I got from Welsh Enterprises (they specializes in Jag parts). After installing the Denso, starting the car, the red light on the voltage gauge shut off and the 'battery not charge' message went away.

The Bosch and Denso look identical. I never would have guessed there was any difference. Apparently there is. For some reason NAPA thought the Bosch was a replacement. It definitely was not. Although it did charge the battery, it did not send the right signals to the car.

Thank you very much for all your help!

 

Trying to Fit a Denso LNC1800AA Alternator to my very early XK8 Coupe. This job fought me the whole way. The last thing is the connector which has a Denso oval. I have two wires a Gray on top and a white under that. I guess the bottom pin is not used on the xk8? Don't want to hook this up wrong. I know there is talk about the alternator wiring here. But cant seem to find the thread.. If someone can tell me the Gray wire is on top and the white in the middle then this horror of breaking the connector can end. This is the Denso Oval Connector. Moderator please help if you can. I am a newbie on forums. Thank-you!!! Great forum!!!! Thanks for being there!

 

Get a new oval connector on Ebay for about $10 and wire it like for like ..it will only go in one way.

 

Hello everyone! Update: The alternator is in. The dash says "Battery Not Charging" (but it is) Also the voltage gauge light is on. I guess this "Denso Rebuild" is an imposter for the Real magilla! After wrestling with this repair for a week. This Jag is kicking my Butt again. The electrical system is half working. Windows doing what they want. Center dash dead. No bulbs light at all. I am Sunk here! Help!!!!! Do I need to call Welsh Jag and drop a months wages???? Any input would be welcome! Have a Great weekend!!!! Thanks for this forum! Certainly a great place for blowing off steam, When your Cat is ailing. (Or when it is not.)

 

After 40 years as an auto electrician I can advise you that the rule is to pick on one fault .solve that and probably the others will also be solved.
So the Ignition warning light. This is connected between the alternator field diodes ..in effect +14v when alt runs and ignition switched live .ie 14v each side the bulb so it goes out. When it is ON it has 12v from the alt and gets an earth thro all the other systems connected to the igniton switched relay. Our ignition switch switches the earth.Normal cars switch the live.
So your task is to find out why the igniton switched relay is not being operated by the key.