My 02 XK8 drains 50% of the battery while parked in one week.

Nothing obvious like courtesy lights not switching off is the problem.

I am aware of the fact that this could be a long process of elimination but are there any common or reoccurring issues to look at first?

It is a California car so not subjected to humidity or rust.

 

Before diving in to a major troubleshooting effort, you should follow the guidelines in attached battery care manual for battery testing and quiescent current measurement to be sure you really have something draining excessive current.

 

Have you had any modifications or repairs done to the car recently?

 

the battery was replaced a year ago the old one had drained completely while I was away for over a month. It was tested and found to be functional but I thought I might as well change it.

no recent repairs or modifications, the car is totally standard

 

Do you own a multimeter with a current measuring capability?

 

Contrary to logic (or at least my logic!), if you arm the security system the battery drain seems less.

Perhaps some systems are set into a 'sleep' mode with arming?

Graham

 

I have had the same exact problem. Let's kill this together.

I also replaced the battery around a year ago after they said it was fine hoping that would be the issue.

I have my multimeter clamped to the + and - terminal and I get .12mA.

 

Something is not right here. Is the multimeter connected in series with the battery? This is how current is measured. Typcial standby current after 60 minutes is 30mA. .12mA is way too low to be real, and if that was the drain it certainly is so low it would not drain the battery for many many months.

See page 16 of the document I posted in this thread in post number 2 for standby currents.

 

I am leaving for a day, I will come back and try and figure out the right way to connect and read this

 

Yes I do have a multimeter, I will measure up the drain and post here.

I will be away for a few days so I am going to fully charge the battery lock the doors arming the alarm and see if that helps.

 

Hello, am I hooking up the ammeter wrong to get the drain? First time i have used one.

 

Your picture shows one possible connection to measure current flow.

However, usually the Meter is connected in series with the + (positive) lead.

Be sure to connect the Tester Leads to the correct terminals on the tester and the correct (Milliamp) Setting.

 

...and do not do anything to create a large current while the ammeter is connected, such as turn on the ignition or try to start the car. This will almost certainly blow the ammeter fuse, or blow the ammeter if it is not fused when you are measuring in the Milliamp range.

 

when I connect the way I am connecting it the car does not get electricity. for example the dome lights are not on. Since the electricity is not flowing I can not trouble shoot what is my phantom draw.

 

Are you getting any reading at all on the ammeter? If not it is possible your ammeter fuse is already blown.

What are all the miliiamp and amp ranges available on your multimeter?

This can be a tricky procedure with some inexpensive multimeters because you may have to start on a higher range and then switch to a lower range once the electronics in the car 'go to sleep' without interrupting the circuit.

 

I just figured out I had to move the red lead on the multimeter to a different input. seems to be acting as expected now. so at least I can start.

 

For my next beginner question. I want to make sure I am reading my multimeter correctly. If I am reading it right at an all off stage I am only drawing 2.18 MA which is way below the below 30 MA that is acceptable. Since it is my first time with the meter I took a bunch of shots to try and make sure I have my scale right. I also took a readings with the ignition on but not cranking.

1. -2.18 = JagMAmp_all_off = MA setting with car all off
2. -.217 = Jag10Amp_all_off - 10 amp setting with car all off
3. -78.6 = JagMAmp_ign_on = MA setting with car all off
4. -7.84 = Jag10Amp_ing_on - 10 amp setting with car all off

 

The connections that you show pertain to the 10 Amp Scale only. But this is OK. Just Convert the reading. The reading of .217 Amp is equal to 217 Milliamps.

To use the Milliamp scale, you must change the leads to the Common terminal and the Blue (Milliamp) Terminal. Then the reading would be directly in Milliamps.

Since the 10 Amp Connection gives you good readings (after converting to Milliamps as described above) I would stick with the 10 Amp Connection. Also, this is less likely to damage the Meter if the current is unexpectedly increased.

 

+1
The readings with the plug in the 10A socket and the pointer on the blue mA acale are not valid.

 

Although it does not mean I do not have a problem but if I remove the key from the ignition and lock the doors while the car is in my garage the drain issue gets almost eliminated.

Leaving the key in the ignition and the doors unlocked has been a habit all my life but it seems that my XK8 does not like that.