Hi I have an xtype 2.0d and the battery light is constantly on its starts about 5 seconds after I start the car and stays on the whole time, i have attached a pic of all the fault codes, would be thankful for any help

 

https://www.jaguarforums.com/forum/x...shboard-46208/

 

more than likely needs new cables. Very common failure on X types. Read the voltage on the back of the alternator where the +cable is after you drive the car and its hot. Then compare against the battery voltage. You will likely find more than .2volt difference. That's point 2 not 2. I always recommend both the positive and negative cables and the link lead that goes from the positive cable to the fuse box

 

Thanks brutal I will check check the voltage at the alternator and battery tomorrow, hopefully that's what the problem is

 

Hi brutal I've just checked the volts from the alternator + to the battry - and its was 12.33v and checked the battery was also 12.33, this was well the car off so am still clueless to what it could be

 

Note the voltages, looks like cable or alternator =

Default Vehicles With 2.0L, 2.5L or 3.0L Engines

The charging system consists of a 120 amp output generator and regulator assembly which generates current to supply the vehicle electrical system with electricity when the engine is running and maintain the battery in a charged condition.The generator is belt driven by the accessory drive belt.

When the engine is started, the generator begins to generate alternating current (AC) which is converted to direct current (DC) internally. The DC current and voltage is controlled by the voltage regulator, (located inside the generator), and then supplied to the battery through the main battery positive cable.

The generator is solidly mounted to the engine timing cover and is driven at 2.8 times the engine speed.Vehicles fitted with manual transmission have a one way clutch fitted to the drive pulley, which prevents torsional vibrations from the engine being transmitted to the generator.

The engine control module (ECM) can switch the voltage regulator between two voltages to optimize the charging of the battery.The low voltage regulator setting is 13.6 volts and the high voltage regulator setting is 15.3 volts, measured with the generator at 25°C (77°F) and charging at a rate of 5 amps. These values decrease with a rise in temperature or current flow.

The ECM determines the voltage setting of the voltage regulator. The high voltage setting is always selected by the ECM once the vehicle has started. The ECM determines the period of time that the high voltage setting is selected for.There are three different time periods selected by the ECM which is dependent upon the vehicle conditions when the vehicle is started:

The longest time period is selected if the ECM determines that the vehicle has been 'soaking' for sufficient time to allow the engine coolant temperature (ECT) and the intake air temperature (IAT) to fall within 3°C (37°F) of each other.

The intermediate time period is selected when the ECT and the IAT are below 5°C (41°F).

The shortest time period is the default time and is used to provide a short period of boost charge.

At the end of these time periods the voltage is always set to the low voltage setting to prevent the battery from being overcharged.The time periods are variable depending upon the temperature and the battery voltage.

The target voltage of the battery varies between 14 volts and 15 volts depending upon the ambient temperature and the vehicle operating conditions. Once this target voltage has been achieved, providing the vehicle has been operating for at least the shortest time period, the ECM will reduce the voltage regulator to the minimum setting of 13.6 volts.

 

Ta for the reply, on the dash test buttons it only ever goes to about 13.6v so it never goes to the higher charging setting

 

I don't think the stalk reads alternator, just battery.

To read alternator voltages you would use a voltmeter on the leads of the battery or connect right off the alternator. To measure battery volts you use the posts.

 

Oo I see, used a multi meter on the battery and it was 12.55v when switched off and 14.10v with engine running but with heaters switched on goes back down to about 12 not sure I'f this has got anything to do with the bat light

 

You should see roughly 12.6v shut off, 15v when you first start it up, and 13.6v after running a few minutes. If that's about what you're seeing and still get the light it's usually the positive battery cable. As a cheap and easy solution you can run a second cable from the back of the alternator to the positive post on the battery. You can get a generic 3ft 6ga cable for cheap at an auto parts store or online. Good luck!

 

Is the positive battery cable extremely hot when you run the car? If so, it needs to be replaced.

 

Hi everyone, Boston here. I've been reading this with quite a bit of interest and now more so as I've run into something close to this and I want to see if anyone has any clue to the problem.
I had a new alternator and battery put in my 2004 x-type late September of this year by a reputable mech near me. The batt light came back on 2 weeks afterward and I brought it back to him and after 2 days we could not replicate the problem. I agreed with him that I should drive it for a while and see if anything happened. Nothing wrong since then til now. It's been a month and a half and the batt light came back on. My readings when I got home were: 12.7 at shut down, I waited 30 minutes and then got 14.36 at re-start with no light on,12.95 with heat on-seat warmer on-rear def on- and door open. Then the batt light came back on and was flashing. I shut off the rear def cause I know that eats up a lot of juice and then reading went up to 13.6 and the light went off. I turned the heater off and the reading went to 13.0. Turned the heater back on and it went to12.9 and stayed there. Shut it back off and it read a steady 12.7. So is my new alternator acting up? Or the new Battery? The pos cable was not very hot to the touch so I'm not sure that's it. Any help would be appreciated as I want to take it down to Fla this winter to use while we're there for 3 months and I don't want to get stranded. I'm just not having a lot of faith that it can make the trip without incident.
Thanks!!!!!

 

Sounds like cable problem. Your testing is a bit too short on time. To really test it, turn every electrical item you can on (lights, seat heaters, climate fan blower, rear defroster, radio). Drive it for 15 minutes. Then leave running and cup hand over cable (DO NOT TOUCH) or pour a very small amount of water on it and see if it "sizzles". Bet you find it does (or hand cupped feels it cooking).

 

Thanks Dell. Ok, I'm out the door to try it. If it sizzles I'll replace it. If it doesn't, then what? But either way I'll get back here shortly and let everyone know how it goes.
Thanks again, I'm starting to feel a little better about this.

 

Well, good news and bad news. I did not get the batt light to come back on, that's the good news. The bad news is the batt light did not come back on so now I'm stuck.
I ran the car with everything on I could to point where my butt was was frying form the heated seats. I drove around for a full 30 minutes and then drove back into my driveway and left it running for an additional 45 minutes while cycling the rear defrost and seats back on if they shut off with the headlights on all the while. Heat was also running continuously on high the whole time. The cables were warm but not at all hot as i would have expected and a small bit of water on the terminals did nothing. So I was able to touch the cable as they weren't hot at all.
So now the question is what do I do now? Like I mentioned, I'd hate to be on the road heading to Fl and have the car crap out on me.
I was thinking I might take it back to my mech, have him do another once over and have him change out the cable anyway. The thing that bothers me is I might be fixing something that ain't broke.

 

Looks like cable is fine based on this ^.
Was the alternator an OEM 3 stage step alternator that you put in?

 

Hi Dell.
That's a good question I can ask him tomorrow. I had him order it and specified that it needed to be an OEM for my year and make. I take it that makes a big difference? How about the diodes, can they have something to do with this? I guess my ultimate question should be, is this ok to take to FL on a 1200 mile ride? I need to decide that within the next 3 weeks and feel confident of my decision. You'd be amazed at how easily I get onto the best Golf courses down there when I show up in this when all the other non Jag owners have to wait!!! -
Thanks buddy, I really appreciate all of this!!

 

Hi Dell.
So as to a quick follow up.....yes it's a 3 phase from O'Reilly. I just checked my receipt that has the item number on it so I looked it up.

 

Then given battery voltage is good, charging is working, cable not overheating, idk what else could be the reason battery light comes on.

I'd check the positive and negative leads in (into) the fuse box and clean them and reattach.

Very, very rarely the negative battery cable will be internally bad (when sheathing is cut off it's visible).

 

Ok Dell, thanks, it was worth a try. I'll keep an eye on it and take over to my mech later today to see what he thinks. I'll let you know if we find something.