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I have a 2011 Jaguar XJL supercharged v8. I was headed back from the store and all dash lights started flickering then the car shut off. The battery was dead so I had it towed home. The tow truck driver was new and tried to jump start it from under the hood 🤦🏻. He also dragged my car into the flatbed while it was in park but that’s a whole mother story! I got the car home and hooked the battery charger under the hood to pop the trunk. I charged the battery with the positive lead on the battery and the negative grounded to the frame. The battery wouldn’t hold a charge so I took it to autozone and they confirmed I needed a new one. Spent $260 a new battery and installed it. I start the car and now I have “charge fault error” a red battery light and red exclamation ❗️ on the dash. I drove the car for About 45 minutes or so and the batter started to get low. I charged the battery and checked the voltage at the battery and I’m only getting 12v. From my research this indicates that I need a new alternator correct?
it just seems weird to me that both the battery and the alternator would go out at the same time. Is there another test I could do? Maybe check the voltage at the alternator? I’m not sure if there are any type of fuses or relays between the battery and alternator that would prevent the alternator from charging the battery. There’s a junk yard close by that has my same car and I can get the OEM used alternator for $70. Any info would be greatly appreciated.
I have a second problem….
A few weeks after purchasing my car the trunk/boot button stopped working. When I press it I hear the click in the trunk but it would not release. I removed the back seats and cut a small hole behind the drivers side big enough to send my daught in 😅🤷🏻♂️ the trunk/boot fuse was blown. Replace it and trunk opened normally for a couple of weeks then it blew again. Repeated the process and replaced the fuse again. I’m on my 4th fuse now but this time when she went to replace it the fused popped immediately. I tried with a bigger fuse and same result. I even tried a 100a fuse and it popped immediately. Any idea what the issue might be with the trunk? Thank you in advance.
I replaced all 4 brakes, battery and possibly the alternator soon. Will I need to take my car to a European car mechanic to have all of these programmed? This is my first Jaguar so I’m kinda learning everything as I go. It was fun replacing the rear brakes and trying to use a c-clamp to retract the caliper pistons 🤦🏻 I now know that they require a tool tow screw them in as pressure is applied.
I have a feeling this won’t be the last that this group hears from me. Thank you guys for any and all help 🙏
...it just seems weird to me that both the battery and the alternator would go out at the same time.
🙏
Well no, a bad alternator will kill a battery - or more accurately a battery will run a car as long as it can without power from an alternator until it's completely dead & often can't recover.
Did you just get this car & did it have faults showing up in the dash?
Well no, a bad alternator will kill a battery - or more accurately a battery will run a car as long as it can without power from an alternator until it's completely dead & often can't recover.
Did you just get this car & did it have faults showing up in the dash?
thank you for the reply. The reason I’m questioning the alternator is because I replaced the battery with a new battery. The battery was fully charged when I installed it and after about 45 to an hour or so(maybe a little longer with ac and radio on) the battery was getting low and didnt seem to be getting charged by the alternator.
with a new battery installed a properly working alternator should keep it charged. When I test the voltage at the battery I’m only getting 12v with the car off and with the car started. Do you know of another test that I can perform to confirm that I need a new alternator before I buy one and do all the work? Thanks
Search the forum (use search tool) for alternator & you'll find previous posts to that include troubleshooting info.
Read the voltage with the car running. The alternator should be putting out 14 VDC more or less (depending on load including battery) with it running. With the battery getting low you should read more like 14.5-ish VDC.
I can't tell you what the impedance should be between the (disconnected) alternator output & ground, but it shouldn't be a short or open.
You could drive it to a mechanic & they can put a tester on it, but you'd need to get it there first.
Do not run your car with the battery disconnected. While that was an option on older cars, with newer cars & electronics, that would damage the regulator (in the alternator).
Even at idle you should be seeing 14-14.5v when putting a digital multimeter across the battery posts. If you use your car regularly (the battery is charged) and it is below 13.5v you almost certainly need to get the alternator checked.
Did you perform the New Battery campaign in SDD? This will affect how your car charges a new battery.
Even at idle you should be seeing 14-14.5v when putting a digital multimeter across the battery posts. If you use your car regularly (the battery is charged) and it is below 13.5v you almost certainly need to get the alternator checked.
Did you perform the New Battery campaign in SDD? This will affect how your car charges a new battery.
I have not ran the new battery campaign in SDD. As soon as I can get the trunk open I’ll charge the battery and drive down to this car shop down the street that specializes in European cars. I called down there and he said it would be $150 to hook the car up and let me know what’s going g on with it.
I never had a Jaguar before and I’m hoping that all it will need is to run the new battery campaign and then the “charge fault error” will go away. Thank you for the response, that’s exactly what I was looking for.
many advise on the trunk/boot fuse that keeps blowing?
To expound upon what clubairth1 indirectly said. Fuses are there for a reason and their value is a critical parameter for a lot of circuit. The main purpose of a fuse is to not let the wiring receive too much current. While I know it is a hard concept for a lot of people to grasp, wiring has a resistance to it for every foot it runs. This value is very, very low (can't be measured on most multimeters unless you get say 500 feet of wiring and you are measuring end to end). But, when you start passing high levels of current through a wire, the wire turns into a heating element (think toaster oven, same concept). You pass enough current, the wiring in your car will do exactly what a toaster oven does. I am not sure about you, but BBQ'ed Jaguar is not a good meal to have. If you are lucky, you simply melt a little bit of plastic near the wiring and only destroy that. On X-TYpes, the battery terminals can get hot enough to cook an egg on it when the wiring starts to go bad. So, your call with running fuses that are higher than what the factory put in.
...This value is very, very low (can't be measured on most multimeters unless you get say 500 feet of wiring and you are measuring end to end).
I don't think they used any super conductors in the harnesses. You should be able to read a couple of ohms across a few feet. Just measure the resistance of the DVM leads themselves and you'll read a couple of ohms.
Any meter that reads ohms should be able to read resistance of basic wire - especially anything smaller than 0 gauge. Your cars harness uses probably 16 gauge (at most), 18 gauge or maybe 20 gauge for signals & low power like window motors & such. You should be able to read a couple of ohms over a few feet. For battery main, starter motor, alternator & other heavy-duty lines with much heavier gauge wire you should see less resistance. But it is there.
Originally Posted by Thermo
But, when you start passing high levels of current through a wire, the wire turns into a heating element (think toaster oven, same concept). You pass enough current, the wiring in your car will do exactly what a toaster oven does.....
The higher the line impedance, the higher the line-loss (heat) for a given voltage & current.
But if the harness lines have such small impedance that you need 500' to read the resistance, you wouldn't have much line loss/heat.
BUT to your points - the rated fuses should never be replaced with over-valued fuses or like you said - burned harness & maybe vehicle fire.
To expound upon what clubairth1 indirectly said. Fuses are there for a reason and their value is a critical parameter for a lot of circuit. The main purpose of a fuse is to not let the wiring receive too much current. While I know it is a hard concept for a lot of people to grasp, wiring has a resistance to it for every foot it runs. This value is very, very low (can't be measured on most multimeters unless you get say 500 feet of wiring and you are measuring end to end). But, when you start passing high levels of current through a wire, the wire turns into a heating element (think toaster oven, same concept). You pass enough current, the wiring in your car will do exactly what a toaster oven does. I am not sure about you, but BBQ'ed Jaguar is not a good meal to have. If you are lucky, you simply melt a little bit of plastic near the wiring and only destroy that. On X-TYpes, the battery terminals can get hot enough to cook an egg on it when the wiring starts to go bad. So, your call with running fuses that are higher than what the factory put in.
I have no problem grasping the concept of a fuse. The fuse blew so I replaced it. The fuse blew again so I replaced it. Then again and again over a 5 month period. The last time I went to change the fuse the fused popped in My hand as soon as it made contact. I tried a couple different fuses and had the same result. I tried a couple bigger sizes as a VERY temporary solution just to open the trunk so I can charge the battery. I had no intention on leaving the larger fuse installed. I don’t know of another way to gain access to the trunks as there is no key unlock.
my concern and question is, what would be causing the fuse to blow so often and now to the point to where I can’t even change the fuse? TIA
A few months ago my wife's '17 F-Pace displayed the same battery problems that your car has, and I followed pretty much your thought train. After replacing the battery, I was still getting low voltage with the engine running, plus the same low voltage warning. I replaced the alternator and the problem was solved.
In my case, I found the old alternator heavily contaminated with oil from a vacuum pump leak that I'd fixed a few weeks earlier. I purchased a new alternator off Amazon, and fitted it myself.
A few months ago my wife's '17 F-Pace displayed the same battery problems that your car has, and I followed pretty much your thought train. After replacing the battery, I was still getting low voltage with the engine running, plus the same low voltage warning. I replaced the alternator and the problem was solved.
In my case, I found the old alternator heavily contaminated with oil from a vacuum pump leak that I'd fixed a few weeks earlier. I purchased a new alternator off Amazon, and fitted it myself.
wombat
thank you for the reply. I’m just gunna go ahead and replace the alternator. The only problem now is trying to get the trunk open with a dead battery and a blown trunk fuse 🤷🏻♂️🤷🏻♂️
Ahem... 5 months you had an electric problem and you did not get it fixed? I am pretty sure you understand that continously blown fuse means that there are an problem? (not just on any vehicle, but same for houses)
Like mentioned: Fuses are protection of the circuit: If the fuse blows there are something wrong on the circuit, not on the fuse!
Only thing you have done by replacing fuse after the fuse you make situtation worse. You propably have now melted wires permanently shot circuited and thats why fuse now blows immediatly. Don´t put another fuse on it: You can burn whole car down.
Seek the fault, fix it and then have happy motoring without issues.
LasVegasXJL, as for why you are suddenly blowing even large fuses is most likely because a wire has gotten damaged (say pinched in a V of some metal) and the body of the car is touching the copper. This is essentially taking any power at the fuse and putting it straight to ground with very little resistance, hence the high current pulls and blowing those large fuses. Unfortunately, normally the answer is hand over handing the wiring through the car to figure out where it is pinched. So, with this being said, I am including a picture of the trunk circuit (this is for a 2012, but should be the same for your 2015). Looking at the diagram, I really see 2 options for what you are seeing. Either the wire between the fuse box and the electronics module is damaged or the module is bad and it is pulling too much current. This is where you can unplug everything on the right side of the module (as seen in the diagram), put in a new fuse (a new 20 amp fuse) and see if the fuse blows (shouldn't). If so, then you know your problem is the wire to the module. If the fuse didn't blow, then plug in the plugs one at a time to see when the fuse blows. That will help narrow things down from there. I would say to look at the plugs and on the plastic of the plugs should be numbers. Find the "1" on each of the plugs. One plug should have a green wire with a red stripe going into the 1 hole. Plug that one in first (this would be the A connector). If the fuse blows, odds are, you are looking at a bad module as the loads should not be seeing power until commanded. You can then plug in the B connector and verify that the fuse does not blow. If it does, then that will be an interesting problem.
Hope this gives you some guidance on how to figure out the issue.
LasVegasXJL, as for why you are suddenly blowing even large fuses is most likely because a wire has gotten damaged (say pinched in a V of some metal) and the body of the car is touching the copper. This is essentially taking any power at the fuse and putting it straight to ground with very little resistance, hence the high current pulls and blowing those large fuses. Unfortunately, normally the answer is hand over handing the wiring through the car to figure out where it is pinched. So, with this being said, I am including a picture of the trunk circuit (this is for a 2012, but should be the same for your 2015). Looking at the diagram, I really see 2 options for what you are seeing. Either the wire between the fuse box and the electronics module is damaged or the module is bad and it is pulling too much current. This is where you can unplug everything on the right side of the module (as seen in the diagram), put in a new fuse (a new 20 amp fuse) and see if the fuse blows (shouldn't). If so, then you know your problem is the wire to the module. If the fuse didn't blow, then plug in the plugs one at a time to see when the fuse blows. That will help narrow things down from there. I would say to look at the plugs and on the plastic of the plugs should be numbers. Find the "1" on each of the plugs. One plug should have a green wire with a red stripe going into the 1 hole. Plug that one in first (this would be the A connector). If the fuse blows, odds are, you are looking at a bad module as the loads should not be seeing power until commanded. You can then plug in the B connector and verify that the fuse does not blow. If it does, then that will be an interesting problem.
Hope this gives you some guidance on how to figure out the issue.
awesome! This is exactly what I was looking for. I’ll be working on the car today and keep you posted. Thanks for the detailed information! 🙏
07-09-2024, 08:21 PM
Need new alternator?
