Maverik Posted May 2, 2023 Share Posted May 2, 2023 So my new wee project car - 1997 Discovery 1 basic spec. I'm tying to piece together the original alarm/immobiliser system. Apparently from previous owner. It didn't have a fob so it was always used on the door key - the back up battery siren started smoking so it was removed by an "auto electrician", the stop solenoid immobiliser was removed and a cable was used to jump from the ignition to the solenoid directly. So, when I got it, every time you opened a door etc. all you would get was a clicking from the passenger footwell. What I have done. Sourced a 2nd hand 10as unit with 1 fob still programmed to it, I pulled the battery off, and swapped the new (with fob) D1 10as unit in, there was also 2 relays missing from the passenger side footwell, which I replaced. I also sourced a new injection pump solenoid immobiliser unit which I've installed. So I've not got central locking working off the fob, and I get 3 flashes from the lights to say the alarm is armed. - the volumetric sensors inside are also working as is all the door switches. so if you set the alarm off you get all the indicators start to flash. I do not however have the small LED located in the dashboard lighting up or even flashing at all. - the stop solenoid immobiliser unit also doesn't ever cut off 12v unless the ignition is off. I also have a battery back up siren - as soon as I plug the siren in, it just sounds off continuously... and I thought the alarm was hooked up to the horns too? but I've not had any sound from them either. I've tried all sorts of tests plugging in and unplugging various items and I've no joy. Even if you're sat in the car and lock it, you turn the ignition on and you get a red flashing key sign, you still get 12v at the stop solenoid immobiliser and you can still start the engine. I've had a good look about to see if anything else has been tampered with but I'm gripping at straws. I've got a borrowed nanocom on its way to see if I can talk to the 10as unit. Anyone have any idea's? Quote Link to comment Share on other sites More sharing options...
Mudmonkey Posted May 2, 2023 Share Posted May 2, 2023 It sounds like it has switched 12v wired permanently to the stop solenoid from somewhere? I think I'd be working backwards from the stop solenoid wire. Have you found the "spider" unit? I think that is between the 10AS and the stop solenoid on the circuit so possibly where someone has been fiddling. Have you read through the electrical troubleshooting manual? That gives you the full lowdown on how it should operate as well as wiring diagrams. Alarm stuff starts at page 251 http://www.landy.ee/manuals/electricity/Disco_Elec.Troubleshooting Manual - LRL0077ENG (1997).pdf Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 2, 2023 Author Share Posted May 2, 2023 53 minutes ago, Mudmonkey said: http://www.landy.ee/manuals/electricity/Disco_Elec.Troubleshooting Manual - LRL0077ENG (1997).pdf Legend! - I've been working off the 95 manual which I think is still referring to the single button keyfob type. 1 Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 2, 2023 Author Share Posted May 2, 2023 hmm on reading I need to look at the horn issue too, as there should be something coming from that. Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 2, 2023 Author Share Posted May 2, 2023 So I got the 10as to go into the simple diagnostic mode by going through the bonnet switch ignition door on off routine which is progress. I'll start to do some circuit line testing I think to try figure out if there's any line breaks. Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 3, 2023 Author Share Posted May 3, 2023 So few steps sort of forward and maybe a few back - I tried plugging a nanocom into the OBD II port and the nanocom didn't light up at all, which suggests its either wired differently to a Defender or I've still got some wiring issues that need followed up. I have however pulled the instrument cluster off and tested the alarm LED and the LED doesn't seem to be working testing it on my multimeter, so this is my next mission to replace/fix. Slowly getting my head around the electrical repair manual I'm going to start poking about some connectors to see if I've got voltage where I should. Quote Link to comment Share on other sites More sharing options...
Mudmonkey Posted May 3, 2023 Share Posted May 3, 2023 I was thinking earlier I've got a mini with the 5AS immobiliser which I assume works in a similar way to the 10AS. The dash led doesn't blink on that and the immobiliser never sets because I have the door switches unplugged, have you checked that all your door switches are working? Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 3, 2023 Author Share Posted May 3, 2023 1 hour ago, Mudmonkey said: I was thinking earlier I've got a mini with the 5AS immobiliser which I assume works in a similar way to the 10AS. The dash led doesn't blink on that and the immobiliser never sets because I have the door switches unplugged, have you checked that all your door switches are working? Good question, yeah I checked them via the multifunction unit and when I managed to get it to go I to diagnostic mode you can open each door individually and the lights flash once each time. The LED looks to be fubar as it won't test at all, don't have any to hand to substitute so just ordered a handful. I'm missing something just not quite worked it out yet, the horn element. Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 3, 2023 Author Share Posted May 3, 2023 A tad more progress, so found another wire snipped going to an earth from the starter relay rejoined and got the starter immobiliser back working. Also found an issue with the BBS battery back up Siren... the Siren only turns off when the alarm in activated amd the hazards are flashing... there's a wire crossed somewhere... literally. Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 7, 2023 Author Share Posted May 7, 2023 So I'm looking for a sense check, can someone confirm what they think the "Theft Alarm unit" is doing in the scenario that the "Alarm sounder" is active... Quote Link to comment Share on other sites More sharing options...
Peaklander Posted May 7, 2023 Share Posted May 7, 2023 It is the Theft Alarm unit that is activating the Sounder Relay and hence the Alarm Sounder. The Theft Alarm switches on and pulls the voltage down, causing the Sounder Relay to energise. 1 Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 7, 2023 Author Share Posted May 7, 2023 11 hours ago, Peaklander said: It is the Theft Alarm unit that is activating the Sounder Relay and hence the Alarm Sounder. The Theft Alarm switches on and pulls the voltage down, causing the Sounder Relay to energise. Awesome thanks you. Quote Link to comment Share on other sites More sharing options...
Maverik Posted May 7, 2023 Author Share Posted May 7, 2023 So I've made some good progress today, I've given up on the battery back up Siren, I've spent enough life tokens on that particular topic, I have however got the alternative Alarm Siren working so I'll settle for that. For info anyone else reading for future. From 96 onwards discovery was fitted with an OBDII port, and the great thing is you can plug a nanocom in and talk to the 10as unit. I was cheeky and used my mates one which had a Defender Td5 license but that matters not, just log it in as a td5 defender and it will open the test function of the 10as and even recognise it as a Discovery type. I successfully programmed 2 new fobs to the original 10as and then I had an alternative 10as which I programmed a new fob too as well. All my jobs for the Alarm are now done for now so here endeth this topic for now.😁👌 Quote Link to comment Share on other sites More sharing options...
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