sbatchel
Member Since: 26 Feb 2014
Location: England
Posts: 25
  
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| Sun Roof stuck open - Battery Condition? |
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There's not much advice out there in internetland for an inop sunroof, other then the 20 second button push that cures all sunroof woes, except mine, so I thought I'd relay my experiences so far:
MY14 HSE.
A couple of months ago the sunroof started to get a bit temperamental, randomly not opening or not closing, but this was reliably cured by the 20 second button push, and I told SWMBO that next time she was over the right side of town and the roof was playing up to call in at the dealers to book it for investigation.
It then started happening a little more frequently, culminating in last night no amount of long button presses would close it. After checking the Fuse I called LRA hoping they'd know more reset tricks than me, sadly not. The attending AA man didn't even know the 20 second button press. We concluded it was a dealer only fix, and we stuck some of his crash wrap over the opening to keep the weather (and birds!) out. (Fortunately I have pretty secure parking)
However, as we were trying a battery disconnect reset I did ask him to check the battery condition with his tester. This came up at 12.4V and stating "Replace Battery", despite there being no obvious signs of battery issues from the car, other than the fact I have noticed the Stop/Start is rarely cutting in, and the engine seems to be taking milliseconds longer to start in recent months. I didn't immediately link the two, and if I had I may have asked him to connect his jump start battery to see if that solved it.
Anyway, I put the battery on charge for a couple of hours this morning, after that, the sunroof closed without any problems. doh!
Testing the battery with my own simple multimeter showed only 12.7V straight after charging, dropping to 12V as soon as I turned any loads on, so I would say the battery is dying.
So my conclusion and advice to the Forum and Internet is: an inop sunroof may be an early sign of battery failure, and if stuck open and the 20 second reset doesn't work then try charging the battery for a couple of hours.
"Ah but shouldn't a running engine bring the voltage up to acceptable levels straight away?" I hear you ask. Well, I would have thought so, but we know how finicky car electronics are these days, and I get the impression that the sunroof module diagnostics don't work once the engine is running, or that power is diverted to where it is most needed, and a failing battery is demanding more so the rest of the systems get less.
And now my question to the forum, where best to get a new battery? Should I go to the Dealer or Specialist Indy who can check that all is well with the power management as well as replace the battery(but cost me a lot more), or is it OK to buy a like for like battery and install it myself?
The reason I ask, is that the RACshop online says that their roadside patrols (who come out to you when you order a battery to be fitted) are unable to fit the battery to the Disco as it is a specialist job and should be done at a LR dealer.
Also, the manual supplied with the car clearly says there is a fuse box behind both glove compartments, and yet I can only find the lower one, and there is no access panel in the upper one.
Did they move it on MY14 cars and not update the manual correctly?
Thanks.
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 15th Jun 2018 9:11 am |
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Oswiperus
D3 Decade
Member Since: 02 Apr 2010
Location: Chelmsford, Essex
Posts: 1590
 
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The battery monitoring system (BMS) will need resetting when a new battery is fitted. It can be done with an IID tool if you have one or dealer/indi otherwise. Stu
2016 D4 Landmark current
2022 Defender D300 SE Gone 
D4 2014 XS Commercial - Gone
D4 2016 hse lux montalcino red - Gone
D3 2005 se java black - current
D3 2005 base manual - gone
D2 1999 TD5 E white - current
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| 15th Jun 2018 9:38 am |
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sbatchel
Member Since: 26 Feb 2014
Location: England
Posts: 25
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Thanks, that's the impression I was getting, though I can't see why the BCM would need resetting if you're swapping the battery like for like.
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| 15th Jun 2018 10:04 am |
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L319
Member Since: 14 Dec 2013
Location: Herefordshire
Posts: 2079
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If the battery voltage is still low with the engine running I would look at the Alternator as well as the BCM.
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| 15th Jun 2018 11:09 am |
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sbatchel
Member Since: 26 Feb 2014
Location: England
Posts: 25
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Good point... If SWMBO would only stay put for 5 minutes I'd be back out with my Fluke 
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| 15th Jun 2018 11:12 am |
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