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Alarm system

Posted: Fri Dec 12, 2008 11:43 pm
by Sidney'61
I was wondering if I can get an alarm system with switches that I can connect to the two interior light switches in the doors, therefore setting the alarms off if the door is opened without it being remotely disabled.
I'm sure it would be a simple but effective design, does anyone know if I can get hold of an alarm system that could fit like that?
Simply two switches and a remote.

Thanks

Posted: Sat Dec 13, 2008 7:18 am
by charlie_morris_minor
from what i understand most car security systems connect to the door light switches ( under the dash is where i seem to rember doing it ) and the battery. When the door is opened the interior light goes on the alarm detects the voltage drop and the alram goes off. Obviously this depends on if your current door light switches work.

Not wishing to break the terms of the message board a "popular" out of town retailer has a system for 69.99 that detects motion / shock and volatge drop.

Posted: Sat Dec 13, 2008 11:22 am
by MoggyTech
Maplin do an alarm called SHARK for £29 and it's very good. Even flashes the indicators and cuts the ignition. You may need a slightly higher wattage interior light bulb, as it works on current drain to trigger the alarms. It also has a shock sensor, which you can enable/disable using the keyfob remote.

Posted: Sat Dec 13, 2008 11:39 am
by MGFmad
MoggyTech wrote:Maplin do an alarm called SHARK for £29 and it's very good. Even flashes the indicators and cuts the ignition. You may need a slightly higher wattage interior light bulb, as it works on current drain to trigger the alarms. It also has a shock sensor, which you can enable/disable using the keyfob remote.
That is what I was thinking - its just a general current drain that triggers the alarm, earlier systems were connected to the door switches or had their own switch to sense an opening door but thats a long time ago now!

I would think that you will need your car to be negative earth before you fit an alarm.

Posted: Sat Dec 13, 2008 12:49 pm
by plastic_orange
My experience with alarms (car and motorcycle) is that they are a waste of time and money - and they will leave you stranded when you least expect it.

Oh, and nobody pays attention to them anyway.

Pete

Posted: Sat Dec 13, 2008 1:25 pm
by grumpygrandad
yes in the middle of the night just when you want it, consider a pump switch then try to remember if its on or off when you start up i listen for that pump tick when i turn ignition no tick then its off ,,grandad

Posted: Sat Dec 13, 2008 4:08 pm
by bmcecosse
The only way it would be useful is if the siren is mounted INSIDE the body of the car - making such a racket that no-one would be able to stay in the car. Certainly bystanders etc won't bother about a car alarm going off. Best protection is hidden petrol pump switch.

Posted: Wed Dec 24, 2008 10:59 pm
by Robins
Yes CHEAP alarms are a waste of money and will let you down by draining your battery. A good quality alarm/immobiliser system has my vote though, they even come with second siren options for mounting internally aswell as out :D . The more security the longer it takes to pinch, and more chance they will get bored or sprung. Having nothing is stupidity, and a fuel cut off still won't stop it getting pinched, just means it goes a few miles before stopping.

Posted: Wed Dec 24, 2008 11:44 pm
by plastic_orange
Sorry, but I stand by my previous post. Alarms are unreliable and will let you down. My bike one cost £300 (don't think that's cheap) and lasted 4 years. I was told I was lucky as they usually only last 3. My Saab's alarm (Cobra) left me stranded - fuel pump wouldn't work as it isolated it and wouldn't turn on after a short stop for the papers. My Golf's one did the same. My mates' experiences are similar, but granted, car ones are marginally better than bike ones. :(

Pete

Posted: Fri Dec 26, 2008 12:27 am
by toginthemog
I fitted a secound ignition switch and key under the dash so if they get it started it will only run till the carb is empty as it turns my fuel pump off thus giving me a chance to just run down the road and batter the fatherless little persons

Posted: Fri Dec 26, 2008 12:44 am
by toginthemog
another thing we used to do was swop the car to negative earth by swopping your battery around to negative earth but you used to have to brush the large terminal on the dynamo with a bit of wire with the positive side of the power this was just to reverse the polarity on charging I now this sounds simple but it used to work. Has anyone else heard of this. we had to do it as radios got better with neg earth

Posted: Fri Dec 26, 2008 8:38 am
by alex_holden
toginthemog wrote:another thing we used to do was swop the car to negative earth by swopping your battery around to negative earth but you used to have to brush the large terminal on the dynamo with a bit of wire with the positive side of the power this was just to reverse the polarity on charging I now this sounds simple but it used to work. Has anyone else heard of this. we had to do it as radios got better with neg earth
Yes, that's right. You also have to reverse the LT connections on the coil and you might have to reverse the polarity of the heater motor. If you physically turn the battery around so the terminals are at the front, make sure the battery bar can't touch them and short them out.

Posted: Fri Dec 26, 2008 1:00 pm
by toginthemog
thats right alex must be getting old things you remember and things you forget

Posted: Fri Dec 26, 2008 4:54 pm
by bmcecosse
Heater motor will be fine - but you should clean the points in the dizzy - and in the fuel pump if you reverse polarity.