aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
  
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| LR4 head unit stopped working - HELP!!!!!!!! |
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As it says in the title, the head unit on my LR4 has stopped working and won't turn on. I had a low battery warning the other day due to hardly using my car during the last 6 months. Took the car out for a 50 mile run up and down the motorway to stick some charge back into the battery (Lucas AGM under 2yrs old)
Switched off the car and went back 30mins later to see if it was a drain issue that had caused the head unit to stay switched off, but sadly, the unit is still not coming on. Checked both 15a fuses in slots 64 and 65 and they're both working ok. Battery voltage was reading 12.9v.
Anyone else had this issue and if so, how was it resolved?
Thanks
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 12th Nov 2020 11:06 am |
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Flack
Member Since: 06 Sep 2006
Location: Preston Lancashire
Posts: 6308
  
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That short run is not enough for a good charge, you need to charge it over night. Make sure your alternator is pumping enough out and that the battery is in good condition.
The screen is one of the first things to not work when low voltage is present.
Also try a hard reset.
Flack 
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| 12th Nov 2020 12:04 pm |
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dewillia
Member Since: 04 Aug 2019
Location: Wolverhampton
Posts: 71
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Try a hard reset has it may have forgot the amp settings etc
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| 12th Nov 2020 12:45 pm |
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aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
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Flack wrote:That short run is not enough for a good charge, you need to charge it over night. Make sure your alternator is pumping enough out and that the battery is in good condition.
The screen is one of the first things to not work when low voltage is present.
Also try a hard reset.
Flack
Not being the best when it comes to electrics, what voltage should I be expecting from the alternator and where do I hook up the meter to check, how do I check the battery is in good condition, and finally, by hard reset, I assume you mean disconnect the battery for 1/2hr and then reattach?
Cheers
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| 12th Nov 2020 1:46 pm |
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dewillia
Member Since: 04 Aug 2019
Location: Wolverhampton
Posts: 71
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Hard reset, take battery cables off connect them together for 25 mins than connect back up
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| 12th Nov 2020 2:01 pm |
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Flack
Member Since: 06 Sep 2006
Location: Preston Lancashire
Posts: 6308
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Hard reset how to in Wiki, but 30 secs to 1 min enough.. Have you got a multi meter, do a search on the board, plenty of info on what you need.
Flack
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| 12th Nov 2020 2:16 pm |
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aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
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dewillia wrote:Hard reset, take battery cables off connect them together for 25 mins than connect back up
connect together?
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| 12th Nov 2020 2:20 pm |
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aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
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Flack wrote:Hard reset how to in Wiki, but 30 secs to 1 min enough.. Have you got a multi meter, do a search on the board, plenty of info on what you need.
Flack
Wiki - as in wikipedia?
Yup - have multi meter, it's the ability to operate it which is lacking 
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| 12th Nov 2020 2:21 pm |
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Flack
Member Since: 06 Sep 2006
Location: Preston Lancashire
Posts: 6308
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Use you meter on the battery terminals check when engine not running, anything below 12.4 or 5 is low, then check again with engine running should be around 14 volts.. meter needs to be on 12 volts DC.
Flack
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| 12th Nov 2020 2:31 pm |
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Johnny Oxford
Member Since: 14 Dec 2014
Location: Chinnor
Posts: 531
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https://www.disco3.co.uk/wiki/Home
aqua0 wrote:Flack wrote:Hard reset how to in Wiki, but 30 secs to 1 min enough.. Have you got a multi meter, do a search on the board, plenty of info on what you need.
Flack
Wiki - as in wikipedia?
Yup - have multi meter, it's the ability to operate it which is lacking
2014 D4 HSE Facelift Corris Grey
Previous :
Discovery Sport SE (awful)
56 plate D3 HSE TDV6 Zermatt Silver
Defender 90 200tdi
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| 12th Nov 2020 2:33 pm |
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aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
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Flack wrote:Use you meter on the battery terminals check when engine not running, anything below 12.4 or 5 is low, then check again with engine running should be around 14 volts.. meter needs to be on 12 volts DC.
Flack
Cheers Mick, I'll have a look at it when I get it back from the MOT tester later today (I'm hoping the screen being off doesn't cause an MOT failure issue!) but the voltage when switched off was 12.9v, so I'm taking that as a good sign so far.
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| 12th Nov 2020 2:39 pm |
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aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
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Johnny Oxford wrote:https://www.disco3.co.uk/wiki/Home
Thanks matey
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| 12th Nov 2020 2:40 pm |
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Owen1183
Member Since: 19 Jun 2020
Location: Stafford
Posts: 35
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aqua0 wrote:Flack wrote:Use you meter on the battery terminals check when engine not running, anything below 12.4 or 5 is low, then check again with engine running should be around 14 volts.. meter needs to be on 12 volts DC.
Flack
Cheers Mick, I'll have a look at it when I get it back from the MOT tester later today (I'm hoping the screen being off doesn't cause an MOT failure issue!) but the voltage when switched off was 12.9v, so I'm taking that as a good sign so far.
You'll need to check battery after 30 mins or so after switching off, to allow the voltage to settle. You'll need to drive the car for at least 30 minutes to charge the battery to a reasonable level (alternators generate current, not voltage)
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| 12th Nov 2020 3:45 pm |
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aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
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aqua0 wrote:Flack wrote:Use you meter on the battery terminals check when engine not running, anything below 12.4 or 5 is low, then check again with engine running should be around 14 volts.. meter needs to be on 12 volts DC.
Flack
Cheers Mick, I'll have a look at it when I get it back from the MOT tester later today (I'm hoping the screen being off doesn't cause an MOT failure issue!) but the voltage when switched off was 12.9v, so I'm taking that as a good sign so far.
So, battery is at 12.9v and 14.9v being generated from the alternator. Battery is now disconnected and +ve and _ve clamps wired together. Here's hoping 
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| 13th Nov 2020 12:26 pm |
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aqua0
Member Since: 02 Mar 2019
Location: Chorley/Sunderland
Posts: 86
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ARRRRGGGGHHHHHH
So, hard reset carried out and still no joy. In addition to the head unit not working, I now have a clock/date that's completely out and I can't do anything about it, and the windows need reprogramming 
Next step is to replace both fuses - 64 and 65 just in case something is dodgy with them even though they passed the continuity test.
What's the next option folks? Is there an inline fuse leading to the head unit hidden away somewhere?
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| 13th Nov 2020 1:23 pm |
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