[nelsonjake59]

I have a 2008 range rover sport that draws power and kills the battery in about 2 hours when it is off. Had the altenator tested and that is good and have pulled every fuse and relay and it is still drawing power. Just curious if anyone else has had the same problem or any ideas what it could be

 

[PJPR01]

Make sure you have not left any lights on in the vehicle...

 

[umbertob]

Are you sure it is not just a bad battery no longer holding a charge, rather than quiescent drain?

 

[RoverGuy7]

2 hours is extremely fast to kill a battery, you sure the battery is in good shape?

Double check the tailgate, make sure both latches are completely latched, and the lower has pulled itself in, make sure the switches are working properly.

Any issues with the alarm randomly going off?

A lot of times draws on these trucks aren't as simple as just pulling fuses, as it's usually not just a component that is 'sticking' on, but rather a module or system that is staying awake or not properly shutting down.

 

[Domex]

When you say you pulled every fuse, I assume you are doing a parasitic load test. Did you also pull the fuses in the fuse box that is located behind the glove box? What is the draw in mA with everything off and all doors closed?

If you pull all the fuses and the drain still exist, the source has to be between the battery and the fuse box. I would disconnect the wires to the alternator and test then check the wiring and relay to the starter.

I've not had this issue on my RRS, but have used this procedure to isolate a bad alternator on a friends car that appeared to work fine but was drawing current when the power was off.

 

[nelsonjake59]

Yes the battery is good it has been checked and is brand new. Have had the test light on the negative terminal while pulling fuses and no changes. Pulled every fuse in the glove box as well

 

[RRToadHall]

A test light means nothing for drain tests. You need a multimeter to actually MEASURE the draw on each circuit. THere are a handful of circuits that will remain live but with very little draw, most circuits will be dead with no ignition. A light just means "yes"... but not how much.

 

[umbertob]

For something to kill a new and fully charged battery in 2 hours or so, it would have to be a major drain, not a couple of modules refusing to shut off IMHO. There's got to be a logical explanation. You could run some tests with a meter to start, and see what results you get. There is a good troubleshooting guide on the forum you can follow, if you are technically inclined: http://www.rangerovers.net/forum/9-range-rover-sport-l320/20371-electrical-issues-basic-troubleshooting-guide.html

 

[RoverGuy7]

I agree with umbertob, a fully charged Interstate H7 has a RC of 130 minutes, so you'd be looking at a +25A constant drain for a couple hours to get to the point where it would struggle starting.

Only thing that I've seen cause that much of a drain(assuming fully charged battery, and that it is not starting after a couple hours due to the battery being discharged) is an internally shorted alternator, which I've seen to the point that I considered a fire hazard.

How was your alternator tested, just output voltage at various loads? Voltage ripple?

Is the draw still there if you remove the power lead to the battery fuse box?

 

[Alpaca]

When you say alternator was tested - how ? I had alternator that was putting out 13.8v but diodes were allowing leak back from battery to ground when ignition was off. Alternator was warm to touch when left overnight. Try disconnecting positive lead from battery to alternator (at alternator side) after car is off - and see if that fixes the problem. Then you need new alternator.

Else if battery if good and you can't measure excessive current in any of the fuse or relay sockets - bad ignition switch could be another area to look (it should be warm when off with that much drain if that's where problem is).

If you have a major wiring short - it should be blowing fuse if on active circuit and you should be able to probe it at the fuse box. There are probably a few more limited areas prior to fuse box where it could be a problem - I'm not sure what's it's called on a rover - but primary current distributor between battery positive and fuse box - make sure it's not wet in there ?

Just for fun - charge battery fully - disconnect negative . Does the battery hold charge in the car ? Then do the same but disconnect positive cable ...

If you are going to look at battery drain as you pull fuses - connect you multimeter in series with positive cable - not ground. I had clamp type multimeter which makes it a bit easier.

I spent days diagnosing similar problem on a porsche - mine turned out to be bad diodes in alt.

 

[Domex]

"If you are going to look at battery drain as you pull fuses - connect you multimeter in series with positive cable - not ground. I had clamp type multimeter which makes it a bit easier."

Why would you use the positive? I've only done it several times, but have always used the ground in series (less chance of accidentally shorting the circuit).

 

[Alpaca]

I measured a big difference at the positive v negative battery terminal - but yes, I was using clamp style meter - when there was short to ground in alternator ...but yes you need to be careful not to short to ground yourself .... (If connecting in series)