Alarming light bars

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t_j

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Hey,

I remember you saying you have your light bars hooked up to your alarm system. Could you provide some details on what you did?

Thanks!
 

The Car Stereo Company

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Hey,

I remember you saying you have your light bars hooked up to your alarm system. Could you provide some details on what you did?

Thanks!
for a price......

---------- Post added at 12:27 PM ---------- Previous post was at 12:05 PM ----------

ok, so i actually had to open up the lightbars. what i did was solder an 18ga black wire to the ground side of the circuit board to each light.( it was a slight project on the rigid to get through the silicone they used to seal the wire hole) this means that the ground for the lights passes through to the new wire. so if the lightbar has ground (and as long as you never disconnect it, which we never do anyways) the wire had ground. i ran that wire to a relay (or you can use a low voltage trigger (like a tr7 which is basically a relay that draws less current) to trigger the alarm. on the relay, i used 85 and 86 as power and ground. one side connects to constant and the other side connects to the wire i put in the lightbar. (it doesnt matter which side goes where as long as there is power and ground) 87a goes to ground and 30 goes to the alarm. so what happens is when the lightbar is disconnected, wires cut, removed, whatever, the relay loses ground and turns off which then connects 87a and 30. (normally closed on a spdt relay) this completes the circuit sending ground to the alarm which will trigger the instant trigger...... and my train horns.....

on mine i did it slightly different. and a little more complicated. i used the ground when armed (orange wire on viper alarms) to an additional relay to trigger constant power for the other relays (one relay for each light) this allows the relays to be energized only when the system is armed. its just to reduce the strain of the relays so they arent on continuoous all the time and prolongs the life of the relay.
 

The Car Stereo Company

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it is really important to make sure you seal the hole back up. all the lights have either hot glue, silicone, etc they used to seal the area where the wires come out. make sure its watertight when you are done. the rigid light was a more hard material than the tmx light so it required more work to get it through
 
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t_j

t_j

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From that I take it that there is too much internal resistance on the bar to wire up the alarm to the positive side of the bar and ground the signal through the bars existing electronics? (If you do this you would need a install a power diode on the positive side of each bar before the alarm hookup point so if only one bar on a circuit with 2 on is disconnected they still go off).
 

cdcalaway

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When I first read the title I was thinking you were going to talk about having your light bars flash when the alarm went off. Maybe a train horn would do better
 
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