help: alarm goes off in middle of night on the 99 disco II

hi, hoping this is an easy fix: last night the alarm goes off (horn blast for a few seconds, stops, blast again, etc). I was able to turn the alarm off with the fob, the driver's door unlocks, I start the engine, drive around the block (to see if there's someone messing with it that cause the alarm to go off). When I park the car, turn the key off, pull it out, the engine is still running. I hit the brake, the engine finally stops. I start it up again, same thing when I turn the key off, and take the key out.

Then, I have the key out, the instrument panel is still lit, the transmission indicating status under the odometer has the D with a line slashed through it, (even though the shifter is in P). More "idiot lights" on the insturment cluster light up, I hit the brake pedal, and they all go out, let off the brake, the same lights come back on.

There's a noticeable clicking sound that appears to be coming from the dash mounted door lock switch, which I notice does not work now either.

I check the manual for any fuses to check, then decide to get out, try to lock the car up with the fob (no luck), but the horn sounds, (like it does when you try to set the alarm before all the doors are closed). So I pull the fuse to the horn, and the fuse for the fuel pump, so the horn doesn't go off the rest of the night, and if someone was infact messing with it, maybe they wouldn't be smart enough to check the fuel pump fuse, so I can go back to sleep.

most post I've come across refer to a problem for the Series I, but wondering if that spider is also in the Series II, since the dealer says the part number I found somewhere this morning is only for the I.

thanks for taking the time to read it, hope I can help with something down the path.

"vesperlandy"
baltimore

Mate had a similar problem .. make sure your battery is completely charged up, they're very sensitive to voltage and power. Also check battery to chassis earth and chassis to engine earth strap .. if they're looking at al ropey it's worth the few quid to change them and get good earths.

Nice to know the newer ones are no better than the old uns.

also has any water got in to the fuse box its common for the windscreen to leak and let water in to it and this also controls the central locking and the some parts of the alarm

and on the other side of the car behind the glove box is 3 more ECUs
1, for the abs
1, for the ACE and
1, for the BCU the BCU controls nearly every thing on the car and this to could be damaged buy water

hughesy said:

Nice to know the newer ones are no better than the old uns.

Click to expand...

Consistency, dear boy, consistency.

thanks all, it's making a lot of sense because it's been raining the past few days, and the windshield (windscreen) does have a drip from the top - behind the mirror, I'll dry it all out, check the battery connections, and see how it goes, many thanks again,

gp

I have been experiencing a very similar problem to the one that Vesperlandy has. Oddly though,there is no evidence of water/wet from either of my sunroofs or windshield.

Looks like I need to get further under the dash to see if its the BCU or fusebox is getting wet...

It's been raining hard in Harrogate since last night and these gremlins have resurfaced after disappearing for awhile.

I reckon BCU too...have similar probs as you...half my dash is out at the moment drying out...new BCU on order as it won't even talk to Autologic!

The indy Land Rover guy in town has identified a very slight water leak behind the fuse box but I thought the BCU was behind the glove box.

Can anyone confirm the location of the BCU in a 2000 series 2?

Could be moisture on door / tailgate /bonnet switces (or corrosionnnnn).

My problem with my year 2000 TD5 has been resolved so thought I would get back with a bit of a post mortem.

The electrical gremlins that I and others have been well documented on this site and many posters have contributed to helping it get sorted.

The solution to my problem ended up being a very light leak coming from the windscreen in the upper drivers side. The water was literally a drop and it was making its way down the pillar and then running down a wiring harness and straight to the back of the fusebox/control unit. Although most posters have pointed me to a BCU behind the glovebox, my problem was on the other side. It was the back of the fusebox.

The water must have been coming in for awhile because there was some fairly well established corrosion. It was causing the alarm, central locks, flashing mileage and various other electricals to malfunction. The malfunctions still only remained when wet and went away after drying out.

We resealed the windscreen without removing it and that killed the leak.

The fusebox/control unit was then replaced with new and then it had to be reprogrammed.

I've attached a few photos to show the part and the damage caused. I hope that this might save someone else a bit of detective work as I suspect I am not the first or last to be afflicted with this particular version of water damage.

This is quite common on DII's,the trouble is the fusebox is more than just a fusebox.It contains an IDM - Intelligent Driver Module.This works in conjunction with the BCU sharing lots of info to output various functions around the car.I diagnosed 2 like this last week,one had no indicators the other would not lock properly.
When you fit a new unit,switch the ignition on and let the IDM have 5 mins to learn the BCU's settings etc before it will work.

new BCU sorted mine straight away