im having a new type issue with my 02 3.0 s type.first i noticed car not quite running great.wasnt sure if i just needed to top off trans fluid since my rpms werent as steady as normally,last time i saw this i found that my trans fluid was a little low due to a slight leak,which was fixed after re-tightening trans(not sure if previous owner had tranny work done).then it stalled out while starting off,but stayed running after only a few cranking attempts ,so i stopped by auto zone to check battery and alt.they said the alt was fine ,battery was fully charged but the scanner read BAD BATTERY.changed it (not brand new)and all was well for a couple days,till it again stalled when starting off,i checked all my fuses etc and all was fine or seemed fine. rode fine after that for a day or two.as i was locking my door couple nights ago,i noticed that my climate control lights stayed on instead of going out after locking or shutting engine off,so i opened the door and shut it off manually.this morning the car was stone dead and after a jump ran great but the message center had a vertical yellow light on next to it and it read" both tailamps failed"or something to that effect and the airbag? light was also on.i have had dead batteries in the car before but never saw any of these type messages etc so i am baffled,thinking maybe alternator??hopefully not computer .anyway car ran fine on my way to drop it off ,messages stayed on the whole way and at one point i heard some sort of chime going off,had plenty of gas etc,first time i ever heard them in the car. advice greatly appreciated

 

Could be bad fuel pump

 

i thought that too before battery died,but just put a new Delphi fuel pump in last december,as well as fuel filter. going to put a new fuel filter in,but this battery drain w/messages etc is kinda weird thank you

 

Have you had the replacement battery tested? These cars are VERY sensitive to battery condition. Sounds like you have lots of weirdness going on all at once. I'd rule out battery condition first.

Re: the battery tester. I have one similar to the type that was probably used on your car. As high tech as it is, sometimes the results are very inconsistent. The tester has a setup menu where you select whether the battery is connected or disconnected. I think the poor tester makes some assumptions when the battery is connected. The results are far more consistent with the battery disconnected. If possible, remove the battery and take it to the store versus leaving it installed for testing.
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One more thought:

Massachusetts, right? The Land of Road Salt and Kennedys. Can't do anything about the latter, but the ground cable from the battery is very susceptible to corrosion damage. Specifically, the bolt that secures the ground cable to the body passes into the wheel well. Road salt wicks up via the threads and gets between the cable and the body, interfering with the connection.

Just for giggles, undo this bolt and clean both sides of the connection. If you see any corrosion damage at the cable crimp, replace the cable.

 

thanks i'll try that now that the battery is out of the car.funny thing is that the car was running great and had just gotten my sticker a couple days before finding battery dead,and all lights were working fine as always.i took the battery out and it is still hooked up to the charger,so ill check the voltage first ,then give it another charge since its been sitting at a friends for a couple days.appreciate the helpful input

 

i checked my battery after charging it out of vehicle and got an 13.8 reading.put it in the car and it started right up,no messages/warning lights etc and when shutting the car off all the radio ,climate control lights went out as they normally did.saw some posts about people finding out that they had bad fuseable link wires coming off the positive battery wire and or bad jbox/fuseable link fuses,so ive ordered a 30 assorted pack from amazon from truck uplifters? for 34.95and going to check out those link wires before changing the alternator or battery as some of these people had bought both to find that it was bad link wires and or fuses causing their problems with draining batteries or alt not charging bat..i lubed the ignition also in case some of the prob could have been in the ignition possibly worn as a fellow member pointed out.will post my results.

 

Ah, perfect, glad to hear the problem has been resolved! I only read this far and was so happy, I thought I'd reply right away without reading the rest of your post. You weren't thinking of continuing to "fix" a problem that's already been resolved, were you?

The preceding was industrial strength satire. It seems you've already got a handle on the problem by making sure the battery was fully charged. But goodness' sake, for the love of Pete, please don't go hacking and splicing the wire harness just because of some hunch. Stick with what has seemed to work.

Now there may still be some secondary issues, such as marginal battery condition (not just the state of charge), a weak charging system, etc. But we can walk you through some tests so you're not just throwing parts at it, if indeed a fault still exists.

How about this totally free test?: Beg, borrow, or steal an automatic battery charger. You'll need something with at least a 10 amp output. (A trickle charger won't cut it) Hook it up every night for about a week. Slightly inconvenient, as you'll obviously have to unhook it each morning. But the trick is to see how the car behaves when beginning each day with a fully charged battery. If good, we can then test the charging system is doing its job and make sure nothing is draining the battery overnight.

But until then, don't go "fixing" anything else. Make it easy on yourself. Consider my personal motto, which has served me well as a professional mechanic: "As little as possible for as long as it takes".

 

My instinct is either a bad wire connection or a bad wire.

On a car of this age and 10x so if it was driven in NE winters I'd first check grounding points. Disassemble, wire brush and clean w/contact cleaner and then re-assemble.
Second I'd check resistance of the main battery wires.


Also, a battery can show proper voltage but still be a bad battery. It needs to be tested under load.

 

thank you guys so much.i truly believe not that my charging system is a great place to start since weird problems started back in september or so which also was due to the low transmission fluid,and also what i thought was only 1 bad front bearing.so i didnt want to invest in a brand new battery,and tires till i was sure all was well with the tranny etc,but i did just change out both my front hub assemblys $75 and one front lower ball joint.my local scrap yard sells refurbished batteries which i had previously in the car for over 2 years with no battery issues,and the price fit my budget only $40 back then,now $55 lol. i had in my head already the possibility of one of those fuseable link type cartridge fuses may possibly be malfunctioning as this person had stated was his source of the battery drainage/alternator not charging full time ,maybe only working on and off.so thats a pretty reasonablely priced option.then of course all those grounding points,have my wire brush and dremel set all packed along with my good soldering gun just in case those fuseable link wires are a possibility.there were a few youtubers and various forums posters that had the link wire problem and ive been working around that area quite a bit and tend to be like a bull in a china shop when im not fully awake or physically and or mentally drained.im actually 68 1/2 yrs old and beaten lol.my buddy has one of those older type charger on wheels with the dials in front that ive been using(not sure if thats a trickle charger)i was an auto refinisher,never attempted mechanical till i bought this ,my favorite car ive ever had.but again thank you guys very much i truly appreciate input from my fellow jag lovers.as you know they can be heartbreakers if you let them.i just cant picture myself not driving this car.

 

That's soooo tough to even try to read

 

sorry,but i appreciate your attempt lol. im still a bit of a basket case,lost my daughter just over a year ago,and still processing

 

As gently and politely as I can say this, i cringe and go into convulsions at the thought of a refurbished battery in a modern Jag. I can't stress strongly enough how finicky these cars are in regards to battery condition. It sounds like you're on a tight budget, but if you can afford a ski mask and a realistic looking BB gun, you could easily round up enough money from your local liquor store to purchase a NEW top-quality brand battery. NAPA Premium has worked well for me. Stay away from discount chain house brands such as Duralast, etc.

Remember, you made one change (swapping out a suspect battery for a fully-charged slightly less suspect battery) and all was good. Resist the temptation to keep looking elsewhere. Go with that theme. Get a positively known-good battery (read: new) in your poor car. This ain't a 70's sedan that was happy with anything remotely shaped like a battery. Like it or not, your Jag is a high-tech rolling computer and has to be treated like one.

 

Yeah but at 68-1/2yrs old he may not get away before the cops show up. And we know the get-away-car isn't running so... maybe plan B is in order.

I do agree with kr98664... 1st thing to try is a 100% known to be good battery. Take it to a parts store where they can check it under load.

 

Let me think this one out cause im still pretty quick ,just not 100% in the commonest sense area again yet lol,but yes i do agree about getting a brand new top of the line battery (thank god for credit cards)and only went with refurbished again because i wasnt sure if there may have been a underlining major issue with the car besides the battery, some of which i mentioned earlier,and wanting to see for sure that there were no MAJOR problems with the vehicle which i since have ruled out.i had been asking about batteries in earlier posts.weird thing is that when this car develops a running issue there is usually a couple ,or few other issues that seem to appear(getting in that high mileage area) that arent related to anything electrical and i find myself completely overwhelmed and have to disect each problem one by one.i was actually still test driving the car after some repairs since september before buying a nice new battery and 4 new tires .had been driving my daughters car most of that time fixing issues with that car before selling it,which i recently have,and now its my time to devote 100% to my jag again.took the car out last night after cleaning all the battery and ground cables etc and all was well but noticed that my heat was not as warm as usual and found that my coolant level had dropped with some wet areas under the hood,so now im on to another issue with the cooling system before making the long overdue new battery purchase.thank you guys and i appreciate the humor,i really do,i believe in staying positive and not surrendering to any of the negativity of others peoples opinion of these gems.just got a 4 wheel alignment through my body shop buds contacts for $55 and he had to drop it off there.he told me that the guy had said that" these cars are shitboxes" to which my bud told him not to say that in front of me cause" he loves that car".ive found that so many people out there think the same thing but i strongly disagree.too many people just seem to quit on them since of course they can cost an awful lot if you have to rely on dropping it off at a shop for even the slightest problems,i met a guy with the exact car that told me it recently cost him $1200 for a fuel pump and that horrified me thinking that they must have had to drop the tank,but not long after i found myself needing one also,did my research ,found a new top of line one for $110 and that there was an access panel under the back seat,took me half an hour.Thank you again guys,really appreciate it

 

How DO i check the resistance of the main battery wires??i should do that as well.

 

 

Thank you,very helpful video,easier than trying to understand the manual. this is the fuse assortment that i got from amazon for $34.95,30 pc.not oem but better than a blown one.