Flat battery - problem solved

[Richard Tanner]

I wrote some weeks ago about the battery on my Range Rover 4.6 going flat every couple of weeks and received some helpful ideas - thanks. Land Rover have had it for 3 weeks now, trying to isolate the leak. They tell me that they have disconnected each circuit but still cannot find it. Now they have replaced the body control unit and find that the leakage appears to have stopped. Their next test is to replace the old BCU to see if the leakage comes back - if so they will conclude that the problem was the BCU and no doubt bill me accordingly!! Any thoughts on this would be appreciated. Thanks.

 

[disco1]

Hi Richard!
A very frustrating situation I must say. I had the same problem with my 95 disco, only it was going flat every 5-6 days from fully charged for no apparent reason, but what I eventually found was that the negative terminal on my battery was a little loose.
Have you checked your battery terminals? It seems you have a leak to earth.

regards,
Roland K

 

[Richard Tanner]

Thanks Roland. Wouldn't that be a great resolution of the problem. I have had several batteries over the past months and would guess that at least one was installed properly but will raise this with Range Rover today. Regards, Richard

 

[JackUnion]

That model has had issues with the fuse panel under the hood, quite a common thing to have to change.
I have to tell you this one.....
I had one in a few weeks back that was towed from a U.S. LR main dealership (I won't say which one!) up to me in Toronto after they had it for 2 weeks and couldn't find the no start problem. It totally amazed me when I found it, someone had replaced the fuse panel for a different problem (see above) and decided to tidy up the tatty wiring harness leading from the bulkhead to it. They had cut away the old harness tape and when doing so cut through a washer fluid pipe (only LR would run the rubber washer fluid pipe in the electric harness). I just happened to wonder what all the new tape was opened it up to see and washer fluid run out everywhere, I pulled the wires apart let them dry and the truck started. Weird or what? how does the old saying go "you don't have to be crazy to work on one , but if you are it helps"!!!

 

[Richard Tanner]

Brilliant story - thanks!

 

[SteveA]

Richard,

Where you live are you in close proximity to other people with garage door openers, remote gate openers, or other cars with remote entry sytems? A few years back Land Rover issued a bulletin to dealers detailing how vehicles left for a few days without starting would run their battery flat. It seems that there is a wide frequency band that the Range Rover monitors looking for the signal from your remote. This signal wakes up the BeCM (body electronic control module) and powers up the computers before you enter and start the car. The problem is this frequency range is also used for many garage door openers, gate openers, etc.

So what happens is if the BeCM is sees atransmission in that frequency band, it powers up. If the vehicle is not started, it will power down again (I think in about 10 minutes). It will repeat that for every signal it gets. Normally this is not a problem, because it would only happen rarely. But, I've had several people with this problem if they lived in a townhouse or apartment d (high density of electronic activity) or lived or worked near airports. I had a pilot who would park his RR at the airport for a few days and when he came back it would be dead. Not a very happy customer.

The fix to this problem is an update to the software in the BeCM, not a replacement. I hope they checked this out first, before they try to charge you for replacement. Now I will say that I have seen faulty BeCMs cause all kinds of problems. If this is all the problems you are having, I think I would just invest in a small trickle charger and a jump box. A lot cheaper than a BeCM replacement.

Stephen

 

[Richard Tanner]

Dear Stephen, Thanks for this. Apologies for the late reply but I have been "off the air". After several weeks of diagnosis, RR have returned the car saying that they have reset the BeCM. They say that they cannot detect any leak after a week or more of testing. I have only had the car back 3 days and it starts fine but the VDU shows "alarm fault" each time the key is inserted. I fear that all is not well. Do you think that perhaps the alarm has contributed to the problem? Living in Hong Kong, we are surrounded by cars and blocks of apartments with automatic gates. that might explain why RR wanted to check the car on site. Thanks for your contribution. Best wishes, Richard