Flashing LED's for alarm.

Stuart McB · Post by **Stuart McB** » 09 Apr 2004, 02:12

My ZX TD avantage originaly had a Citroen alarm fitted but over its 11 years this has gone to pot. Some one preivious removed all the wireing except for the LED in the dash on the drivers side by the ignition switch. My question is, can I fit any thing that will make this LED flash when the car is locked up? more as a deterant then and actual alarm. You know just a visual sort of thing. No techno speak as electrics was never my strong point. I have a maplins near to me in the next big town. [:)]

andycarter · Post by **andycarter** » 09 Apr 2004, 02:18

www.maplin.co.uk
Search for part no UN42V, 12V flashing LED.
You may or may not be able to successfully dismantle it and connect it to your existing LED but at £1.99 it got to be worth a shot
Actually, forget that! RE06G is much cooler at £4.99 [8D][:p]

sooty · Post by **sooty** » 09 Apr 2004, 15:10

I used these Flashing LED's before for such as this, but the problem is going to be to find a live feed when the ignition is switched off and live off when ignition switched on.
A few times I've had to use a small relay. So when the relay is not energised the normally close contact supplies the LED via a live feed, and when the igition is switched on the contact changes state to open and the live feed is switched off to the LED. The relay is operated a feed from the ignition switch feeding such as the glow plug circuit or similar as this is the only circuit live when on the third position.

VLL · Post by **VLL** » 09 Apr 2004, 21:26

Had a 12V flashing LED connected to the ignition wiring at the ignition key in a previous car (Wont mention the make here), which would start flashing once the ignition was turned off.
Just get a tester and see if any wire becomes live once you turn the key to the off position and all you then need to do is pick up a neutral from somewhere.

Post by **philhoward** » 09 Apr 2004, 21:32

Try running a LED with positive to the live feed to the ignition switch, then the negative to the ignition switched live. When the ignition is on, both sides will be equal voltage (i.e. no current will flow = no flashing); with ignition off, there should be enough leakage current allowed into the ignition circuit (relay coils, etc) to run the LED with no ill effects whatsoever.

Stuart McB · Post by **Stuart McB** » 10 Apr 2004, 01:10

Thanks for the all the info. That flasghing LED part for £4.99 is just the sort of thing I'm after. Have printed off the details and it's off to Maplins tomorrow with the wife and my wallet. Again thanks for the info.
Also gives me some thing to do this bank holiday as I have spent to day decorating the living room for the wife. Looks orange to me but apparently it's "tapestry thread" in colour. Don't really remember that one in school art class.

Stuart McB · Post by **Stuart McB** » 11 Apr 2004, 20:45

Went to Maplins and guess what niether part in stock. Any how tested the LED that was fitted and it already had the built in flash unit. So had a look about and followed instructions as per philhoward. Found a permanent live and a switched live wired up and hay presto nice and flashy. Have put in line switch so can turn off when in the garage etc. Looks good and cost nothing, Agai thanks for the info.