2007 XK Convertible BRG

Sometimes when I go start the car the battery has discharged over night.

I've had the battery checked a couple times and it's less than a year old. I think I may have narrowed it down:

If I leave the car's HVAC system on I think it's draining the battery, It's only recently started doing this after I resolved the blower motor (rusted from the duckbill issue).

I had a BMW X5 that did the same thing until I replaced the HVAC resistor.

Is this a known issue?

 

No but you can use threads about battery drain or parasitic draw to find the cause.

 

+1 on searching this forum for other reasons that cause battery drain.

Use a battery maintainer if the car isn't used for long periods and lock it as well using the remote. Keep the remote at least 30 feet (10 metres) away from the car to make sure the systems completely power down.

 

Thanks, I've looked, the symptom doesn't appear in the threads I've read.

 

Certainly but the process is the same. And since you know when it started, take a look at this thread
https://www.jaguarforums.com/forum/x...e-%245-184627/


And if that doesn't do it, a slow but tried and true method is set up your ammeter and perform a parasitic draw test.

Here's a video that covers it in case you haven't done one.

 

The thing about using an in-line amp meter is that every time you detach the battery and attach the meter, you reset all the electronics and they come back on for awhile. Using an Amp-Clamp is much easier. My F-150 had a parasitic draw and I tried for days using in-line and it sucked. I got an Amp Clamp and it was SO much easier.
Amp Clamp meter at Amazon

 

Read this thread: https://www.jaguarforums.com/forum/x...-hours-224077/

Even though your battery is less than a year old, it might have never been fully charged. Many brand new batteries sit on the shelf for months discharging before they're sold. And if you usually make short trips, your alternator might not have fully charged your battery. In that case, you should use a battery maintainer to keep your battery fully charged.

 

On my XK 2007, I left the headlamp switch on the AUTO position over night.
Seems the headlamps would come on intermittently.
Next morning batt voltage was 10.9 v and the car would not start.
Be sure that you turn the headlamp switch to OFF position before locking the car.
Worked for me!
Bob

 

This car doesn't sit for more than a 2-3 days, 90K+/_ miles, had the car for 30K pretty much trouble free miles in about 3 years.

Had a clockspring issue when I bought, easy fix and restored the steering wheel while at it.....damn that's hard to keep clean.

Replaced the top, cause the glass came unglued...new top!

Rear speakers don't work...but haven't bothered to look into it.

Problem with the duckbill....will fix that when it needs my attention....won't be get hot for a while and there is good info on that here. Great site, if I haven't mentioned it before!

BT module is kaput, or needs resetting all the time, I don't use it anyway, the connection to the stereo via the radio works well enough for my needs and the BT function is way behind the smartphone tech anyway.

After the last few weeks, it doesn't appear to be either the light switch (eliminated that earlier) or the HVAC.

I'm beginning to think it's the starter motor giving up the ghost. I went out for a quick errand a few days ago, fired up from cold morning start good and strong, made my stop and came out to start the car to come home, and doing...it barely started, dash lights up, ebrake does it's thing and power steering requires more effort than usual (sort of an odd symptom, but I'm sure the computer is telling it something about speed) and the radar doesn't want to work and the trip odometer resets to 0. Got it home, turned it off, waited a couple minutes, pushed the start button and it fired up like brand new.

A few days before I went to start it in the morning and it was as if the battery was dead. I had other things I could do so I let it sit and figured I would hook up my spare battery later. Came out that afternoon and thought, what the hell, let's see if the battery is still dead just for the hell of it. Fired up right away, good and strong even after sitting around four 3-4 hrs.

I guess that's why they call them gremlins.

I might have to finally get multi meter out, I know how to use it....on simple stuff, this may not be simple, but if I can narrow it down it may save me some money before I take it to my buddy's shop. Wouldn't mind doing a starter motor replacement but not if it's not what's wrong.

Don't know this site well enough to find things easily and the thread on electrical issues hasn't been fruitful.

TIA to you all.

 

Its a right PITA having to constantly have these jaguars on charge all the time , but the price we pay for not driving them more

 

Bump.

So it's not the battery.

It's definitely a starter circuit problem; either a relay or the solenoid/starter. This car is not garaged and it's cold out this time of year.

I've gone through a few different start procedures.

A I'll go out and while sitting in the car, door closed, push the brake and start button and it fires up, no problem. Sometimes it starts right up with strong starter motor spin sometimes it barely turns the engine over.

B Other times pushing the button kills all the dash lights and nothing happens, then I take foot off the brake push the start button and everything lights up, turn it off again and then push the brake and start button and it turns over laboriously but it'll start, sometimes not. Every time I go through somethings happen, some don't. Sometimes the front lamp system blinks, sometimes the parking brake becomes engaged (I don't normally use it) and needs to be disengaged. . Usually the trip odometer resets it's self and the steering assist is as if it was in higher speed mode (I assume it has a speed sensor for steering assist).

C Sometimes, even after it's run for a while and it's warm, it'll go through the same process, usually not.

This morning, after no having been started since Saturday, it took quiet a few times and different procedures to get it started and run without having to jump start it. The parking brake engaged and would not disengage, I had to turn the car off and restart it for it to function again.

 

A regular issue with earlier models has been the HPPM (High Power Protection Module) where megafused connections from the battery to the starter motor have slackened or the cable terminals begun to break up. The result has been intermittent starter motor issues. The XK is a more complex design but has a similar battery fuse connection known as the BJB (Battery Junction Box):




Worth checking and eliminating the connections as a possible cause.

Graham

 

Hmmm! Let me see!

I'll get back to you, thanks!

 

Also, if not already checked, grounds. I had this happen to me once last year, turned out to be a loose ground in the boot.

 

Okay, so got around to removing the BJB about a month and a half ago, took it apart smudged some NOALOX paste on the contacts, put it back together, reinstalled it and haven't had the problem reoccur since. I've let it sit for up to three days, cranks right up, no accessories failures so far.

Thanks for the tip GGG!