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Up Topic Open Technical Section / C1 Technical Chat / Dead Alarm
- - By chrisg Date 05-07-2007 17:50
Hi All

My alarm has finally given up the ghost, luckily the bikes at home so it didn't leave me stranded somewhere like some that I have heard of on here.

I was wondering if anyone knows of a bike mechanic that would be prepared to come out and disconnect it for me, or if anyone on here fancies earning some money at the weekend (Or when ever it's conveinient) please let me know.

I live a few miles north of Heathrow, West London.


Parent - - By bolt-on-billy Date 05-07-2007 21:08
if its the bmw alarm then you should just be able to unplug if from under the dash. 4 philips screws and half a dozen torx :-)
Parent - - By chrisg Date 05-07-2007 22:46
Hi Ya

Thanks for the advice, I tried that a few months ago, Steve on here sent me some pictures of the plugs to disconnect it but it seems that I have different plugs than the usual ones. We couldn't identify which ones were for the alarm so I think it's better if I get someone who knows what they are doing to do it for me.


Parent - - By bolt-on-billy Date 06-07-2007 10:15
if you post a pic of what you have then we can tell you whats abnormal. most alarm units can be unplugged from the loom for ease of replacement, what does that do :-)
Parent - - By chrisg Date 06-07-2007 16:02
Hi Ya

Do you want me to post a pic of the conectors behind the head light or behind the dash?


Parent - - By bolt-on-billy Date 06-07-2007 16:20
if you have them them post whichever but a dash side picture gives a clearer impression of whats in there - is your alarm behind the seat? if so a pic of that would be usefull. chances are they are designed to immobilise the bike when there's no power or a unit failure. just need to backtrack the wiring and pull it all out. its the kind of thing you'ld take the panels off tonite spend half a day sorting it out then re-assemble. its worth the effort as calling someone out will cost a fortune.

the bmw system uses the bottom big grey connector and only uses a couple of wires. the expert on the wiring is adrian and he'd be able to tell us where the wires go as unless you have an A3 monitor the online pdfs are a pig to read.

a non bmw system though will be chopped into the ignition wiring, the kill switch and the indicator circuits.

the more pics you post the easier it is for us diagnose online. if you can shrink them yourself then do so. if you lack the software then install the windows powertoy
Parent - - By chrisg Date 07-07-2007 09:50 Edited 07-07-2007 09:54
Hi Ya.

As you can probably notice this is a picture of the conectors behind the head light.........

Sorry I forgot to let you know that this is the standard BMW alarm.


Parent - - By bolt-on-billy Date 07-07-2007 10:19
they've been moved around from bmw standard layout. I think its the clear flat block on the right stack with the red and white wire coming out as thats the cutout circuit.
Parent - By chrisg Date 07-07-2007 12:32
So do I just unplug it?
Parent - By Sven Soderberg Date 08-07-2007 18:05

I also have a dead alarm system (BMW original). It won´t start. I just bought the bike so I´m not so familliar with it yet. And I don´t have the "riders guide" to it, so I wonder if the "transponder-key" has some kind of battery that needs to be changed? Or must I unplugg the system like You have suggested? 

Sven Soderberg
Parent - - By bolt-on-billy Date 10-07-2007 20:50
yes you should just have to unplug it and in theory it will go back to normal. I would take the dash off and track the wiring incase its patched elsewhere, but the red/white wire is linked to the cut off circuit and as far as I'm aware thats it. also you can have a look in the fuse box and battery compartment for the alarm power supply as again that should kill it.
Parent - - By chrisg Date 11-07-2007 15:22
Thanks Billy.

I'll let you know how it goes.

Parent - - By chrisg Date 19-07-2007 09:10
Hi Ya.

Tried to disconnect the alarm by unplugging the connectors under the dash but it didn't make any difference, I think it disabled the alarm but it also disabled the bike. I've spoken to BMW technical and they said that it can't be just unplugged as that would make too easy to steal, they said that the alarm wiring has to be removed and then wires added to bridge that gap left by the alarm as it is hard wired into the loom at the factory.
Vines of Guildford quoted £250 all in to remove it as it takes about three hours labour. Trouble is is that they can't do it for four weeks and I need the bike badly for working in London, at the moment it's costing me a fortune in traveling and parking fees.

So if anyone knows of a mechanic that could do the work and ideally be able to come to me in Heathrow although I will get the bike to them if I have to I would really appreciate it.


Parent - By jp72 Date 19-07-2007 11:53
when I buy my second C1 its alarm was disabled. I asked the guy at BMW Mottorad to reactivate it and he did it for free! (well almost, 1000km service wasn't :) ).

IMHO it should be possible to do the reverse operation aswell. I think you have to unplug the alarm and reconnect a free hanging plug under the dashboard in place. Try to see if a matching plug is present under the dashboard.


Parent - - By timo Date 19-07-2007 15:00
You are in London right.  Just walk it down to the corner, and camp out across the street, behind a bush.  When some low life walks up to steal it, wait until he has deactivated the alarm, and then jump out of the bushes, and run him off. ;-) ;-)

Sorry, I could not resist.  It is funny that most 15 year old low lifes can deactivate those alarms in 5 minutes, and it takes a BMW trained mechanic 3 hours.

I hope you can get it sorted soon.
Parent - - By bolt-on-billy Date 19-07-2007 19:18
I havent seen a diagram of the loom so I cant tell where its patched in - a decent auto electrician would be able to do it for you a lot cheaper. we keep asking for the installation instructions but have never got em - maybe airwin could ask the germans if they have a copy of it.

basically the alarm hijacks the ignition controls so there must be a combination thats easy.

if the weather wasn't so awfull I'd be tempted to come over and give it a go for you in return for petrol costs and a nosebag :-)

there must be a way of bypassing it so maybe the blue and brown wires just need twisting together but if it needs deinstalling then I'll come over and maybe see if I can suss it out :-)
Parent - - By airwin Date 19-07-2007 21:03
I posted the manipulation some time ago on this forum, and indicated the wire to reconnect when you unplug the alarm. That seemed to upset quite a lot of people on this forum so I deleted that post some time afterwards. I did found this solution on a german public C1 site where nobody seemed to get upset about this information being available in a permanent matter. It must still be there.
Parent - - By bolt-on-billy Date 19-07-2007 21:24
you sure it was this one? I cant see us getting upset about being able to disconnect something we dont like :-)

its probably nothing more than bridge the brown to the red/white wire.
Parent - - By beamish Date 19-07-2007 22:32
Get a new Thatcham alarm fitted. I bet they'll disconnect for free when they fit the new one, and you'll get a discount off your insurance.
Parent - - By chrisg Date 20-07-2007 10:18
Hi All

Just bit the bullet and paid £260 to have it completely removed from the bike. I used Pat Keenan at Mobitec ( and can thoroughly recomend him. He drives a 7.5 ton lorry with a full workshop in the back complete with the Mobitec computer. He'll come to you anywhere within the M25 with no charge for traveling. He charges the same as a BMW dealer which is quite steep but he is fully BMW approved.

I'll get another alarm fitted when I can afford it but for the time being I'll use it as is, I don't leave it anywhere where it will get nicked as when I'm working in London I park it in the company's secure underground carpark.

All the best

Parent - - By bolt-on-billy Date 20-07-2007 12:17
did you watch him so we know in future? :-)
Parent - - By chrisg Date 20-07-2007 13:47
Yaeh, sort of.
He basically striped out the alarm and all the loom that it was attached to, then he unplugged a couple of the plugs under the dash and joined them together.
He said all the alarm loom has to be taken out because the alarm bites into the ignition line in three places and that just unplugging the alarm plugs under the dash won't work, I said to him about how can the theives do it so quick and he said as far as he knows it could be done by shorting out two plugs under the dash but it only works while the ignition is turned on and it doesn't work reliably, as soon as the ignotion is turned off it resets its self and you have to keep doing it to start the bike, hence why when they are stollen the dashes are left loose, he also said that it can damage the ECU as it is effectively shorting out the alarm and ECU. Unfortunately he said it won't work with a faulty alarm and the only way of re-imobilising the bike is to remove the alarm and loom totally.
Parent - By timo Date 20-07-2007 16:31
Glad you got it sorted, sorry you had to go to that expense.  Have fun riding it to work now.  That is the important thing.
Up Topic Open Technical Section / C1 Technical Chat / Dead Alarm

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