disabling through antenna

I was informed that theives can disable an alarm by using a jumper box, and running 12 volts through the cars antenna. If this is true, then how can it be prevented?

Haha, that sounds like a good way to do nothing. Even if they grounded the battery that they were using to "spike" the antenna with to the frame of the car, all it would do at most is blow out the tuner in the radio.Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

I was wondering, because even though it seemed like a ridiculous idea, i thought it might be possible that it would end up sending voltage to the accessories of the car, causing the alarm to think it was running. As a safeguard I thought of maybe adding a diode to the accesory input of the alarm.

Don't even worry about it, it can't do anything. Like I said the most it will do is blow the tuner section of the radio. Also even if it did send power to the accessories, and it won't, that will not help the thief disable the alarm. Certified Security Specialist

Always check info with a digital multimeter.

I promise to be good.

Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Tonto26, These are my thoughts and suggestions to your fears. I will not tell you exactly what area's of the vehicle need to be addressed, but will offer a few things you should incorporate into your system, if you want to be protected from these sort of threats. These simple techniques will protect the alarm system, and those compoents that you require to be a deterrent. The feed-back I am giving you is based on many years as a professional REPO man. Every alarm system I have encountered in 10 plus years all exhibit the same faults and no installer from California to New York has ever addressed these in a day to day installation. Only those who I have spoken with, or shared information via forums such as these have had more chance of me not disabling their system in under 60 seconds. This isnt an guarantee, that it wont be taken. If it takes us more than 3 minutes to deactivate the system from the time we say go. I just simply tow it... 1) All outputs from the alarm CPU which interact with the vehicle system(s) should be fused. Stepped fusing is ideal. 2) Shunt isolated / voltage regulated power supplies powering the alarm will provide stable, and secure power source. 3) An isolated ground plane, also known as a floating ground. Will prevent ground loops, and feed-back. 4) Ferrite core beads placed onto critical wiring will reduce RFI interuptions. 5) A direct secndary *chassis* ground strap, that you see on most rear end of the vehicle's or similar placement will ensure a steady ground plane, and bleed off residue static discharge. 6) A powered back-up siren is a must, assuming any of the above is not in use. To provide a last line of defense, in alerting you or others of an attack. 7) As a last line of defense to a alarm failure, and to protect the vehicle from being taken (not from being towed though) is to ensure you have physical devices that are engine, fuel, ECU, etc switches / fuse(s) that must be activated to operate the vehicle. Regards EVIL Teken . . .

I doubt if 12 volts into the antenna would do anything. I was hypothesizing a high voltage surge into the antenna.