1.Windshield wipers come on one cycle each time I start the car.They then go off,once engine has started??

2."Drivers seat belt warning light" no longer stays on when seat belt is not worn and driver is sitting in the seat.

3 "Rear trunk compartment lights" when trunk is open,most often nothing,no lights in compartment come on.
Now if I was to unhook a terminal on the battery,then re-hook.The lights most always come on as they should.I wonder if due to a low charge on the battery?

4.Car seems to have a short or a drain?Battery is always dead when i go to use the car and at times only 3 days after I last drove it.This has gone on for years,even with a new battery.When it was last replaced it lasted the longest.10 days or more.Guessing...

5."Best way to find a short"If I was to put a volt meter on the battery with the trunk lid open.Read voltage,then remove one fuse at a time.Will this help me find the short on a Jaguar and be safe on car?
Simple back n forth checking the meter each time a fuse is removed,to see if voltage jumps up.
I know that some items such as a clock or?will be pulling power from the battery at all times.So would not necessarily be the cause of a short once i removed its fuse and seen a small jump up on the meter.
That I do need to know what each fuse it while doing this.Also so that I would know what circuit is bad and to check the wiring on.
QUESTION IS:This is what i would do on old muscle cars.This will not harm anything on a 2000 Jaguar XK8 would it?
I have been told that this is a no no on Jag's,but really do not see how it could do any harm? But then again it is a Jaguar!!

Thanks!
Hope you all had a safe and happy Halloween.


2000 XK8

 

You're not going to see a significant change in the voltage, but you would see a change in the amperage. You'd have to remove the red battery cable and connect the meter in series between the cable and the lug on the battery. BUT DON'T TRY TO START THE CAR LIKE THAT! You'd blow up your meter. If you have something draining the battery the meter will probably show a few milliamps of current going through the meter. Then you can start pulling fuses. When you get to the circuit that's draining the battery you'll see the meter drop to near zero.

 

I'm not sure if you're that familiar with electricity, so to expand on what I just said, think of electricity like water flowing in a pipe. The voltage is the equivalent of water pressure, and amperage is the equivalent of the flow rate. You can have high pressure with no flow, such as when you turn off the valve. If you turn on the valve so the water is just dripping, you still have the high pressure on the other side of the valve, but if you had a limited supply of "water" (such as in the battery), eventually all of the water would drip out.

An ammeter is the equivalent of a water meter, and just like a water meter is in series with the water pipe, the ammeter has to be in series with the electrical circuit (Actually, that's not entirely true, but for our purposes here let's just assume it is). The electricity has to flow through the meter for the meter to measure how much electricity is flowing through the wires. That's why you need to take the + cable off of the + terminal and put the meter in between. A digital ammeter is very sensitive and you'll be able to detect tiny amounts of current flow.

Sorry if I made that sound too simplistic. You may understand the concept, but someone else might read this a year from now and the explanation will help them.

 

Thank you Reverend Sam.
I have a Actron CP7672 digital multitester that I was going to use.
What should the meter to be set to for doing this?
Meter between Pos. battery lead and pos. battery post.
Meter says on it DVC. ACV. DCA 2000K,200K,20K,2000,200 10A hFE

The DVC ACV and DCA all have a number/scale range with them.
Thank you.
twist

 

I will give my standard answer to any electrical problems. Replace the battery with a new one that has been on a battery tender (or floating) for a couple of days to make sure it has a DEEP charge.

Good luck!

 

I downloaded a pic of your meter and used yellow to indicate which settings to use. Since the battery drain is so low you'll probably use the 200 or 2000 microamp setting (the funny looking "U" symbol). I doubt that there's enough current to use the 20m (milliamp) setting, but you never know. If you're meter is set to the wrong position it will give you some type of error message in the display. On Fluke meters it says "ol", but I'm not sure what the Actron meter will say. If it isn't giving you a number then just turn the dial up to the next higher setting (clockwise).

You want the leads plugged into the two holes that I circled. The top hole is just for measuring higher amps. I'm not sure if the Actron meter is polarity sensitive. If it is, it will give you some sort of weird reading in the display. If that happens, just swap the two leads.

 

Some nice help there Rev!

Hemi, I had similar problems with my A6 for 3 years....went through 3 batteries under warranty. The car would sit for a day, usually no more and when I tried to start it, it would be difficult or wouldn't start sometimes.
The dealer tried everything, eventually, they think they narrowed it doewn to a poor earth connection and I think a poor connection to the starter motor if I remember correctly......Anyhow they did this work and everything seems fine to date with no problems to report

 

I just thought of something. I might be wrong about the meter setting. If the battery is draining down in three days, that's a pretty significant leak. I'm not sure how many amp hours these batteries hold, but let's say they are 72ah. That equals 1 amp per hour for three days. You might actually have to leave the middle hole empty and plug the second wire into the top hole. The dial would then be set to the 10 amp setting. I underestimated how much current it would take to drain the battery in three days.

 

Thanks,I guess that for now I will unhook the battery and put a slow charge on it.
And then take it in to get a load test done on it.Or the other way around.Time pending.I like it parked.The mileage seems not to go up and it would make a nice trade in.This draining issue and the front suspension issues that I have had.The past owner"Mom"had taken it to them"dreaded dealership" repeatedly with over the YEARS with, no luck.She said that they said that they had put the biggest battery in it.I wish that they would had found why they feel it needs this large battery,just to start a relatively low compression engine?
Dead weight is all that it is.
The big battery was just a bandage once again.She was a good repeat customer.
Unlike her son..ditto..

 

I had the same problem with my 99 XK8, 3/4 days w/o running usually resulted in a flat battery. After getting no satisfaction from the dealer, I purchased ( I have a serious tool addiction) several test instruments to help isolate my problem.
1.) Midtronics PBT-200 battery tester. It can detect bad cells
2.) Mini AC/DC Clamp Meter DC amp two ranges 10 and 100A. 1mA resolution at 10A
Clamps on any wire lead including the battey lead.
3.) Fuse Buddy Automotive Current tester - 20A max with 10 mA resolution.
Pull fuse, place fuse in tester, plug tester into fuse slot, read current draw.
I measured 280 -330 mA draw at the battery with everything off including the boot lights. Spent a lot of time looking including checking the heated O2 sensor relay.
I never was able to spend enough time checking every circuit before I sold the car and purchased a 2003 XKR.
My "live with it solution" was to pull the negative battery cable whenever I had to travel. A two minute task to pull or replace and reset the windows.

Good luck on your investigation

 

Most tool places, like Harbor Freight or Northern Tool, sell battery shutoff switches. It's a knob that you attach to your battery lug. Then the battery cable attaches to the knob. All you have to do is turn the knob to completely disconnect the battery.

 

I use to own a quarter mile A/fuel and alky dragster.Division 3 NHRA.And have had many 1/4 mile early Mopar Hemi,bracket only cars.I know all to well what you are talking about,as far a liking tools or having a shut off switch.A man is only as good as the tools he owns right!I have already installed a simple hand dial shut off to the post.This would be a dealership fix I take it?

So far my only investment is 4 new tires and new shocks up front and top plates.Car was a gift.They would not give squat for a trade in,so i ended up with it.My daughter likes the car,so I use it to pick her up from after school National Jr. Honor Society with the top down.Yes i am bragging on her,very proud father!I guess the suv blended to much with all the others?

I was more after a correct fix.
Thanks for the ideas.As said it had been to the dealership MANY times over the years from past owner"Mom".And they just kept selling her batteries.
After a true fix.Mom only drove to the store guessing once a week or less, so I may have a now bad battery because of?
This battery must be going on 2 years old guessing and has been drained sooooo many times,that as said it may be the problem.
I have a doctors appointment this morning so will bring the battery with me and hit the parts store and have them load test it.That is one tool never invested in.
Thanks for the ideas.

 

Battery was only at 4 volts when taken in to parts store.They "Autozone"charge and test for free.They kept it overnight and gave it a slow trickle charge.It charged up just fine,but failed a load test.Bought a 7 year Duralast.All is well. Thanks

 

another one fixed by a new battery, good news.

 

Did you solve this problem HemiTwist?
I have a similar one in a 01 XK8. Sometimes the wipers come on when the car is parked and switched off. They sometimes continue until the battery is dead. I solve this by pulling the fuse and replacing it when I need wipers! The mechanics have worked on the wiper motors and replaced the switch that returns the wipers to park after the ignition is switched off. But that hasn't worked. The car has had a history of strange little electric problems - like the seatbelt light coming on and the ABS light coming on - and then going off.

 

I think you ought to keep that one. The kid not the car.

 

When I boought my '98 XK8 4 year ago the previous owner told me I had to run the car every 3 days or the battery would go dead. Said it was a quirk of the Jags. This was told to him by his local mechanic/gas jockey. At that time the only thing I found wrong was the trunk lights not working. Through testing I found out it was a defective switch. Changed it. Have had the car sit for 3 weeks in the middle of the winter, while on vacation, and never had a problem. I do shut off the auto lights when the car is going to sit. I figure there must be power going thru the sensor to make the switch work. Jack