Battery drain - help/advice needed!

HELP! I have a 2007 4.2 SC (brilliant piece of kit by the way!). I have posted this on an existing thread re. battery drain but no replies yet. Apologies for the long post but I'm hoping someone has the answer. Bought the RR early September, no electrical problems. First really cold weekend in December, car would not start on the key turn, dash lit up like a Christmas tree, lots of messages about various faults, then it started after about 5 seconds. No gear selection and various other systems turned off. I turned the ignition off and tried again and the car started as normal. This happened a couple more times, then got the AA out. Battery tested and 'good' but needed a charge. Current draw 9 amps with everything off, AA man went through the fuses (in the front) and when he pulled the fuse for the nav etc the current dropped to less than 1 amp. Leaving this fuse out has solved the poor starting problem. Car in at LR dealer last week, nav unit would not take the software update that I was told should sort problem. Whilst poking around the tech found that the upper tailgate was sticking meaning that the interior lights stayed on, this was sorted and he thought this might solve the current drain but.......it hasn't! Poor starting issue again with fuse replaced although not as bad as the first time. I have checked the fuse and it was a 15 amp instead of 30 so I have changed it - could this be the problem? So, that's the full story! I also appear to have the HVAC issue with the fan remaining on. As these things appear to be 'known issues' I am inclined to take LR on as I think that they should repair at their expense. However before I spend more money allowing the dealer to run a 'full diagnostic' (their words) I am hoping someone out there can help?

The amperage of the fuse will make no difference, if it's too small it might blow but that's all. Sounds like the Nav unit is duff. Fan running might be fianl stage resistor, don't really know as I have a P38. If you only got it in September, I'd throw it back at the dealer, it should have had a warranty anyway but the sale of goods act may cover it.

A duff battery will cause all sorts of havoc.

Thanks for your reply. Do you think a new battery would solve the problem, given that the original is now more than 4 years old? Also I had no problems at all until the cold weather.

Ruffy said:

Thanks for your reply. Do you think a new battery would solve the problem, given that the original is now more than 4 years old? Also I had no problems at all until the cold weather.

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Worth having the battery tested under load but batteries typically die in cold weather. If you change it get the biggest battery that will fit with the highest Amp Hour and CCA and not from Halfrauds.

Quick update. Full battery test by Land Rover dealer has confirmed that battery is u/s. New one being fitted at the weekend, however this will not solve the problem as battery drain too high with fuse 49 back in - although it will help. Does anyone think that an auto electrician could isolate these circuits when ignition off to prevent drain?

Ruffy said:

Quick update. Full battery test by Land Rover dealer has confirmed that battery is u/s. New one being fitted at the weekend, however this will not solve the problem as battery drain too high with fuse 49 back in - although it will help. Does anyone think that an auto electrician could isolate these circuits when ignition off to prevent drain?

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Well he could probably remove fuse 49 as you have done to reduce the drain. Range Rovers are generally beyond general auto electricians experience,so I would use a Range Rover specialist (not main dealer) if you arent prepared to tackle it yourself.:scratching_chin:

What has not been mentioned here is the period of time they take to go to sleep,earlier L322 models take around 16 mins to shut down - is this being taken into account ? The sleep current ought to be down to less than about 50mA,but often there are large spikes as various ecu's shut down.
Pulling out fuses is not really a good idea as you may set faults etc which will only confuse the issue,plus when you put them back in you will be waking things up which restarts your 16 mins.
Auto electricians seem to struggle with LR products,(And rarely have full diagnostic coverage)if the dealer cant/wont sort it I think you would be better off finding an independant by recommendation.

had same battery drain....turned out the satnav was sh@@ged..fitted 2nd hand unit,,,alll ok sofar