shorting out siren output cable

Hi, is it possible to prevent a thief from frying my alarm brain by shorting out the siren output cable? If so what can I do to prevent it like a fuse or diode? I have a Viper 5902.

Really, what's the point?  If a thief is to your siren wires whether they cut them or short them your alarm will be ineffective. 

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Kevin Pierson

Because I have a good gps tracking device and the viper smartstart module that will still be running if they do get to the siren. My system also has 3 backup batteries. My siren runs off a relay which wont drain by backup batteries and they would have to completely take apart my car to get to the brain and batteries. A 4 to 5 hour process. They will be caught in time but I would hate to buy a new brain because they shorted my brain by shorting my siren. So how can I stop them from shorting the siren cable?

Assuming a hood pin is installed, that should trigger the alarm. If the siren doesn't scare them away, they are going to find it and cut the wires running to it.

If you are so worried about a cut siren shorting out your alarm then put some greenfield or similar flexible conduit around the siren wiring.

Yes hood pin is installed. Well if some one could answer this it would be great. If I install a 30amp fuse on the siren wire coming out of the brain would that fuse pop and no harm would be done to my brain if they do short the siren wire?

if your siren is run off a relay, the relay will prevent feedback to the brain. no work needed

blanx218 wrote:

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if your siren is run off a relay, the relay will prevent feedback to the brain. no work needed

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Simple.

Siren circuit should have fuses or current limitation to prevent that technique.

And that is why there is usually a 2nd siren....

KP gets the cigar, if they can get to your siren wiring, it's all over.
Hence stealth the siren and it's cables, my siren is beside the battery and pointing down to a wheel arch it's cabling is stealthed up.
It's also a battery back-up type so even if they cut the wires it will still carry on for about 20 minutes.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

You mean systems only have ONE siren/annunciator?

I always fit at least 2 noise makers - not including any deafeners for inside the vehicle or building (with warning pips to avoid heat-attacks if false triggered).


The theory - short or cut one siren but the other still blasts away.
(Then there are satellite sirens - self powered and require the central unit to turn them off (ie, if cut the trigger and remain on).

These days I tend to favor internal hi-dB beepers. Not only do they get intruders out quicker, but people seem more curious than yet another typical alarm. (Only if not heard outside do I add external annunciators.)

Of course one has an internal 120db to fry the brains of any scal who gets that far.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

If you are that worried about the brain, make the brain trigger a relay, and have that relay power the siren.  If you do want to fuse the brain output wire, a 30 amp fuse would be waaaay too large of a fuse.  If you have a single electronic siren, try a 5 amp fuse.