Hello.. Im throwing this out there for some hopefully helpful feedback. I recently got a brand new interstate battery but it will not hold a charge. If I let the truck site for more than a day, its dead as a door nail !I have not added any auxiliary wiring at all.

Any ideas?

 

First, check the battery terminals are very good. id go as far as taking them off and redoing them to be certain. Also, the big fat earth straps. check those.

To confirm it is a current drain, take a multi meter that shows current, and attach it inline with your positive cable and positive terminal.

set your multi meter to read current and see what the reading is.

Be very careful not to activate any functions while this is hooked up. If you draw too much current, you rusk blowing the fuse in the meter. While not catastrophic, having to go out and get a new fuse is boring. ie, dont turn on the blower etc. Interior lights as you open and close the door should be fine, and you should see the readings change as you do that.

With things in this situation, and your reading a current, you can start to eliminate whats causing any potential drain by removing certain vehicle fuses, which narrows down the culprit.

 

I've attached the Land Rover technical service bulletin for diagnosing phantom current draws on the battery. (It gave me an opportunity learn a new word -- quiescent.)

In some ways it wasn't a huge help, but it does give some pointers about diagnosing the problem you're having.

I had the same problem that occurred off and on for years and years. In the case of my truck the problem turned out to be that the shop that had removed the original air springs and installed coils in the rear failed to change the setting in the SLABS computer. As a result the self-leveling system would periodically try to run the air springs compressor and drain the battery. Did your truck ever have air springs?

On the other hand your problem sounds like it might be something else given that it's happening so regularly.

I preferred to connect the meter between the negative post of the battery and the negative cable. Get back to us if you're not sure how to use your multimeter to read amps.

I'm afraid that tracking down these problems can be a painstaking exercise. Good luck, and let us know how it goes for you.

 

Good idea to wait for the system power down before switching meter to mA range.


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I recently got new to me Rover with the same problem as mln01 described - look for a box under the drivers side near outside of the frame rail at the b pillar - if its there that is likely the problem. You can do a search on my post and find my cheapo solution to the problem or you can have a shop reprogram the BCM.

 

If you have switched from air bags to springs and have not turned off the SLS in the computer then it can cause a battery drain. I had the same issue before I went and had the SLS turned off. There is a black box attached to the frame under the driver side of the truck that contains the compressor and valves for the SLS. When the truck is off do you hear any clicking or noise coming from that area?