Hi All,

I'm beginning my investigation of a battery drain on my '03 which is being caused on a circuit fed through Fuse 20 in the DS interior fuse panel. I've done all the prep work to troubleshoot it down to this point - alternator and battery are new and working properly, replaced key fob battery, etc. Draw is between .24 and .5 amps with fuse in (fluctuates quite a bit), and is a steady .012 with the fuse out. Truck did not come with SLS, so this is not the culprit, nor is the ABS pump drawing much after the vehicle has been shut off.

Using the D2 circuit diagram document, I've printed out and marked all systems that I could find that feed through Fuse 20, so that I have a plan to disconnect each to see what makes an impact. But there's one related to the AC that I'm having difficulty with.

On page 82 (Section 38 - Air Conditioning), connection C0590-6 with a GP wire, goes to 'G'. Flipping to page 84, 'G' is now a P wire, and goes to the Air Temp Control at connection C0791-1. First, is this an error? The wire colour changes from one diagram to the next, with no header or component in between. Second, does anyone know what this circuit does? All others in the diagram go to something, but this one seems to be just a wire from the fuse box to the ATC, with no description about it.

Just thought someone might know. Thx in advance.

 

Fuse 20 - Purple - to header 725 - to purple to C0791-1, listed as battery supply for the ATC, page 1200 of 1529 in the workshop manual. But that is in the first circuits manual for the D2. Guess the ATC needs some meory battery power. Fuse 20 runs a lot of things that have tiny "vampire" brains (clock, radio memory, some of the OBDII port, etc.)

 

Still trying to find this drain. I've disconnected every component and system that runs through Fuse #20, with the exception of:

- Shift interlock
- passive/transponder coil (battery in key fob has been replaced)
- ignition switch light

I hope to try these this weekend, but it's starting to look like it might be an individual wire in the harness, rather than the component itself. If I pull the interior fuse panel, will it be possible to isolate specific wires at the panel, without having to cut them?

 

I'm getting ready to install a dual battery system in the Disco, so I thought I'd drop it off at an automotive electrical repair shop to see what they can find. They went through the entire circuit serviced through fuse 20, tested all the components along the circuit, and measured the same drain I saw.

They disconnected the battery and let it sit for a week with no power, charged up the battery outside the vehicle, and re-installed the battery and the 20amp fuse. They've had it for a week since then, without any drain on the battery. They removed the fuse and measured the draw, which now seems to be normal. The mechanic told me he's seen this same behaviour before on some American vehicles, but this seems anecdotal.

The only two possibilities I can come up with are:

- disconnecting/reconnecting all components, and the wiring connectors along the circuit path, has removed a short somewhere.
- some component wasn't resetting or shutting down properly, and it took the extended no-power period for it to reset properly.

Neither of them are good in my mind, because either of them could re-occur again. At least I'll have the dual battery system in place and I can self-jump if needed.

Any thoughts or experiences are most welcome!

 

OK, I think I might have found the culprit by accident. I removed the plastic trim panel above the pedals, as I kept hitting it with the toes of my boots. I figured if I removed that, I'd have more room under there (it worked....wish I had done this sooner). Of course, the OBD connector is mounted on this trim piece, so I had to move it out of the way. Low and behold, I saw a couple of wires spliced into it that were definitely not part of the OEM harness.

Turns out that a PO had installed a GSM tracker that appeared to be still transmitting. When I finally found the unit stuffed up under the dash, it was warm to the touch and had a couple of blinking LEDs, so it was certainly drawing current.

Fingers crossed that was the cause of the drain.

 

That's incredibly creepy. Have any pics of the little monstrosity you pulled out?

 

Here's the complete unit. The piece with the round end is the transmitter, and the rectangular part with the white lettering is a lithium ion battery backup.



Here's the transmitter without the casing, clearly showing the SIM card used to access the GSM network:



I'm sure the NSA already knows I've removed this, without having an agent with an account on LandRoverForums.com.