Battery problem?? Tailgate problem??
 

I recently had to replace my battery after my Mrs left a parking light on that completely drained it . I fitted a Yuasa silver battery that was recommended for my car (X5 3.0 2005 ) . All was ok for about 6 weeks then if the car was left for a day it doesnt have enough power to turn the engine over ? Any ideas what could be draining the battery ?
I also have an intermittent issue with the tailgate popping open ? Tends to happen more in damp/wet weather and will do it 4or5 times nearly every time I open the doors ? Any help will be appreciated .
Ps ive had the alternator checked and is reading over 14amps

I've had problems with a stuck button on a key fob causing random tailgate open and alarm.

Historically the # 1 cause of drained battery is the FSU aka FSR.

You can measure the resting voltage after resting overnight to see what values before and after. It's much easier than training down current drains.

To do that I have a magic tool you plug into a fuse spot and it measures the current found through that fuse (which is temporarily put into the tool)

The FSU is the cause maybe 60-80% of the time and takes 5-10 minutes to pull it out. If you take it out and no overnight drain then put it in and have drain problem solved.

Do you lock your car at night? If locked the tailgate will be disabled, if unlocked or won't be allowing for a malfunction to draw power

Hi Andrew, what is the FSU/FSR and where is it ? I lock the car every night but I don't think the boot lock problem is connected with the battery problem as I only get the boot issue when I open the doors .
Thanks
Jim

Do you get boot issue when open door with key in the door or just with key fob? I suspect key switch in that case.

The FSU is directly below the head unit of the radio. Accessed from the right side of the transmission hump under the dash. Find a YouTube video basically you pull off the carpet panel right side of transmission hump and it's pretty far forward against the firewall.

It has a big molex connector and unplugs. You'll see why people call it the hedgehog when you see it.

If the spikes are conical it's original and way overdue for replacement the new ones have many more spokes and they are cylinders.

Hi Andrew, Ive just searched the FSU and seen how to replace it , it seems to suggest that there was a problem with the blower motor not functioning or staying on after the ignition had been switched off , ive never had any issues with the blower , do you think this will still be the cause of my problem ?

The bootlid opens of its own accord , I open the door with the keyfob theen physically open the door and while getting into the car or sitting in the car the boot will suddenly unlock , this can happen a few times after closing the boot again ?

I have issues some times where I shut the top hatch and it pops right back open as if the button is being pressed.

I have a feeling your issue is a malfunction in the release microswitch.


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More often than not there are no symptoms related to blower when FSU is staying on and pulling power 24 hours a day. That fact is why more often than not a mystery parasitic drain is the FSU.

It's not a mystery when you have no high speed fan then for sure it's FSU

The second and third are the TCU and the NAV if you have them. Pull the fuses and see what happens.

Thanks for all your help guys , I'll have a look when I get a chance and post back what I find