Disco 1 Possible alarm issue?

Yesterday, when opening my D1, when I put the key in the ignition, what sounds like a vehicle reversing alarm is sounding from under the dash, until I turn the key, same when I turn the vehicle off, until I pull the key out. I had a quick look when it first started, but couldn't see anythign obvious.

When locking the car, I'm now getting 2 loud chirps from the alarm, the car locks fine, but sometimes it continues with a single chirp every few seconds until I unlock, othertimes no further chirping.

I've noticed the flashing LED on the dash has been doing odd things too, sometimes it is staying on solid after locking or flashes really fast until I unlock other times, it will act normally.

I don't know if it has an aftermarket alarm system fitted, or if it is factory/dealer fitted.

I'm not having any issue with it starting and all doors lock on the fob. The rear wiper and demister have stopped working too, but not sure if this would be related or coincidence.

It had been in the garage for MOT and some welding, but I know the battery was disconnected as I had to sort out the radio, so don't think it would be related to that, as it was fine for the few days last week I used it after getting it back.

It is a 1997 300tdi auto with EDC

Has anyone got any pointers for me to have a look at tomorrow while I've got a day off?

Many thanks.

Sounds like an earth or other connection problem, maybe to do with damp.
But no direct experience, as tomorrow is coming up soon, maybe @discool will jump on as he seems to be the Disco 1 guru.
Best of luck.

If it’s a early one upto to 92 it doesn’t have a factory fitted alarm system, after 92 it did
Easy way to check is look up where the front interior light is and you should see two ultrasound
Sensors in a pod, if it has these then it’s factory fitted,
Usually after market alarm systems have there sensors fitted lower down on the dash,

I should have said, I don't know if it is the aftermarket (Toad) alarm or factory fitted system that is playing up, as it has both, but looks like it is the factory system that is playing up, as it is that alarm that chirps.

Had a look this morning, but it is a right jumble behind the fuse box cover, there is a large silver box that looks like it goes into the wiring with an adjustment screw for sensitivity, a G-shock sensor connected too, but the fuses aren't fitted I chucked a couple of fuses in and an aftermarket LED came on, so Im presuming this is all to do with the aftermarket alarm system. I removed the fuses, as that LED has never worked since I've had the car, so thought I'd leave it like that.

I have another box screwed to the lid, which I'm not sure if that is part of it too, or possibly something similar to a Ron Box, but not sure.

I can't hear where the alarm is that sounds like a reversing alarm, but definitely down around/behind the fuses.

I now have the car not starting, I'm turning the ignition on and when I go from acc to start, the ignition lights come on at a point, but off again when in start position and the only light on is the EDC light.

I've locked the car and disconnected the battery (don't know if that will help reset anything), I'll leave it about 1/2hr, then go start checking through things again.

I'm in 1/2 a mind to bypass the immobiliser and alarm system for something of my own design, but not sure how the EDC would be affected and if i'd have to change to change to non EDC pump and injectors.

I had a 96 Disco 1 that would occasionally not start so I did the spider bypass which solved it. Didn't have your other issues though.

Can you PM process if you don't want to put it on the open forum please?

It was about 10 years ago when I did mine but if you google "disco 1 spider bypass" there's lots of info about it. It is a bit of a faff as it's buried behind the radio but not particularly difficult.

Check drivers door switch/wiring is OK. If it thinks door is open will stop rear wash wipe and make warning buzzer sound with key in ign

I thought there wasn't a spider in the later Edc auto?

Leaving the battery disconnected while I had lunch did nothing, so I got to work with it all.

Looks like the issue was the aftermarket Toad alarm system, I spent this afternoon cutting the insulation tape away to trace the wiring, cut out the wiring and remade original wiring and was all ready for the school run. The "reversing" alarm has stopped when the key is in the ignition (I read this is mandatory DOT requirement for American spec, but possibly stil fitted to all vehicles, but not always activated?), the chirping has stopped when locking the vehicle and the LED is acting as normal.

Toad alarm box, wiring going into other parts of the harness.

Nest of wiring, horrible mess and best removed!

Toad alarm system removed, ready for bin. It seems to consist of an immobiliser, G-shock snensor and some sort of GPS/antenna, as well as the siren.

Much tidier in there now, presuming the box on the lid is some sort of tuning box? At leaset, something to investigate at a later date.


Rear wiper is working too now.

Only thing seems to be, I've now got to wait for the glow plug light to go off before it will crank, but I can live with that and have a look another day.

At least the car has been in the "broken" and "being fixed" stages, so is now back into "about to break down" stage

I reckon you've done the right thing taking the Toad alarm off - the factory system is complex enough, without all that extra "stuff" in there!

I'm having issues with the electrics on my 97 D1 Auto too - and they sound half similar - the two chirps from the factory alarm mean it thinks a door or the bonnet is open - the rear wiper not working is the same thing - the wiper is inhibited with any door open.

And yes, no spider on the auto EDC.

And no EDC on my D1 auto either - cos I took it orft

I'm getting the intermittent EDC light on when driving and throttle doing it's own thing, going anywhere from idle to about 2000rpm and back down, I think it is the throttle potentiometer, so my cruise control isn't working, From what I've read, you either can't get a new unit or they're hard to get new, obviously used is an option, but may have the same issue, other option is to try to get teh specs for the potentiometer and cross reference it to see if there is an alternative that could be used. For now, going non EDC is a last option.

asp383 said:

For now, going non EDC is a last option.

Click to expand...

Fair enough. IME, the weakest link is #4 injector ERR3377 - if you see a good used one, might be worth getting it.

Removing the EDC is simple enough - change the FIP and injectors, fit a FWIC and a EGT gauge, get it all tuned up, enjoy 150 ish Hp and better fuel economy