Quick oddity I'd like to ask about;

Last Saturday I tested my battery while I had it disconnected to install the rebuilt throttle body assembly. It tested super weak even though the car started and operated fine (12 volts and 50% charge). The battery is exactly one year old. I topped off the charge while I was doing the work and then put it all back together. I drove it around for a while and then garaged it for my work week. Now 6 days later I decide to drive it to get a haircut and tested the battery first. I got 12 volts and 49% charge. I figure I've got a drain somewhere. I decided to start the car. It fired up the instant I twisted the key with no codes etc., ran beautifully to where I get my haircut. Fired up instantly after my haircut and ran beautifully all the way home (maybe 12 miles round trip). I tested the battery when I got home and it was 12.6 and 95%. I don't think the alternator could charge it that much in 12 miles?

I tested an older battery in my garage and got about the reading I expected but my leading theory is that the charger I own is giving me false readings. Obviously I'll take the car for a free reading at a local auto parts store to confirm but I can't really do that before a cold start. Any theories other than a faulty charger reading?

 

There is a shutdown / go to sleep sequence the car goes through as you remove the key as a ground signal is provided to the Security module with pin 5 through pin 4 in the ignition switch . Notice if you have the seats retract back and column tilts up that the shutdown sequence has started otherwise the car stays awake draining the battery . First try is to spray lubricant in the key barrel to free up this switch .

 

I had that option disabled but I just went to the garage and turned that option back on for a test. It does in fact work; when I turn off the ignition the seat goes back and the steering column moves up. Does that confirm that its going into sleep mode? Does that eliminate that as a possible problem?

 

Yes that does as the 4 to 5 pins are closing giving the SLCU a ground through the ignition switch .
There is a possibility that the column does not go fully up ( binds ) to satisfy that it is at it's fully up physical position as it must satisfy the position sensor to continue with the shutdown sequence

All the interior lights off including the trunk lights as this happens alot ?

 

Interior lights fade off normally. I put my phone on video and closed it in the trunk, light went out. I just tested the battery again a few hours after I parked it; down to 12.3 volts and 70%. The car shows no sign of the battery dropping. The only indicator I have is the info from my charger/tester. I guess I'll get my multi-meter out and test for a drain. I just hate to disconnect the battery again, it just re-learned fuel trims etc. and is running great. Oh well.

 

Before you were to reboot the battery you can verify that you don't have a stuck closed King relay . Verify that the ones circled in red click as you cycle the ignition switch . The one that doesn't click by feeling it is most likely stuck closed draining the battery
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That's awesome, thanks! That will be a project for tomorrow for sure. I have a box of extra fuses/relays etc off of various parts cars, I hope there's one like that in there just in case I find one not working.

Thanks again,

 

I could only find two (2) of those relays on my car. The passenger side rear heelboard doesn't have one (driver side does) and I can't find the second location in the engine compartment. The two I did test clicked when the ignition was turned on. Didn't hear any sound when the ignition turned back off. Same for both.

I can't figure out which fuse will turn off the trunk light. I can't do the drain test with the trunk light on and I can't get to the battery without the trunk open. I guess I could remove the bulb...

Never mind. I just pushed the trunk latch with a small screwdriver and it shut the light off; car thinks the trunk is closed.

Great, so I disconnect the battery and go to test with my multi meter, the fuse inside the meter has been blown. My son is the last one to use it but it may have been blown from when I used it before. I guess I'll go fuse shopping.

 

The wiring guide for 2002 :

http://www.jagrepair.com/images/Auto.../jagxj2002.pdf

See page 37 for any differences

See page 39 for the king relays , keep in mind that not all circuits go through the king relays and are hot at all times like for example the trunk lights .

And page 89 for the trunk light switch and if I recall is common beyond the other issue of the wiring shorting out as it follows the right trunk hinge arm under the hinge cover . The power source for the trunk lights is provided by the BPM and is looking for a ground through the trunk switch ( or a common chaffed wire in the hinge )

 

what am I missing? If the trunk light goes out (you put the cell phone in the trunk and recorded video), it isn't the trunk light. Years ago (told this story many times) I put my 4 year old in the trunk of a Bavaria to beat on the door if it got dark . . .

Why are you convinced you have a problem . . . again, please, I am slow . . . .?

As an old member, Danielson, used to say: "these are just cars, drive em. quit looking for problems!"

 

On the 200 Ma scale the screen reads - 004.6 and if I turn the trunk light on for reference it reads - 012.0. I confess I really don't know how to read multi meters very well. Is this considered high enough to qualify as a parasitic draw?

 

Jim, I just wanted the trunk light disabled because otherwise it would be on while I was accessing the battery for draw testing. The battery being in the trunk and all...

I don't suspect the trunk light as a problem.

 

There is a value as the car is asleep of 30.0 MA Correction Requested

There is a good training guide on the use of a meter by the makers of Fluke brand meters .

http://en-us.fluke.com/training/training-library/?jobtype=15591&page=1&filtLevel1=&selectedTab=vide os

looking up link for your multimeter type / range .

http://en-us.fluke.com/training/training-library/test-tools/digital-multimeters/digital-multimeter-fundamentals.html

Fluke training video :

https://www.youtube.com/watch?v=-llMmSsDNPI

 

It's also possible that the battery itself could have a defect. Most places have at least a 2 year warranty on those batteries, it can sometimes be a hassle to convince them it is actually a warranty issue, but they should eventually replace it if that's the case. I've had a battery fail in about a year and got it replaced under warranty. If you're really motivated and have a spare battery or other transportation, you can top it off out of the car, then leave it overnight, unplugged, and test it in 24 hrs or so. That will help isolate a defective battery as a cause.

 

You have to use the Ampere scale (with two decimal points, better three like what Fluke has) on the multimeter and leave it connected for at least 1 hour. If trying with the 200 mA scale, the current from the battery will probably blow the multimeter fuse as there are current spikes of a few amperes at the time of connection of the ampere meter and then it goes down quickly to less than an ampere and, slowly over one hour, to less than 30 mA. See the attached document for current measurement procedure (it has a typing error which I have corrected).