# Got another car alarm question



## dmroberson (Jun 24, 2004)

Just bought and installed a Viper 791XV car alarm with remote start, for my 04 Sentra 1.8S. Question is, anyone know anything about the DEI 508d Proximity Sensor? I'm thinking about getting one and adding it to my car alarm, but not sure if it's worth it. Supposedly it uses radar to monitor movement in and around the vehicle. BTW Ebay has it for about $40, retail is about $90. Any help would be greatly appreciated. Thanks.


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## Punkrocka436 (Jul 8, 2003)

proximity sensors are usually garbage. They will warn someone who parked next to you getting out of their car. The only external sensor i would use is if someone were to stick their hand in your open window (good for convertibles, or if you leave your windows/sunroof/t-tops open alot


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## samo (Apr 30, 2002)

A proximity sensor uses an electromagnetic field to detect if something enters the perimeter around the vehicle. The best prox sensor on the market is supposed to be Alpine, but DEI makes an excellent one as well. The main use of the prox is to warn approaching individuals that the car is armed. Another use is to scare off the neighborhood cats if you park outside. If the sensitivity is set correctly, they can be very useful. However, 99.99999% are set far too sensitively, and thus false constantly, completely eliminating their usefulness. Although I don't believe in alarms (aside from tracking systems such as Compustar and the DEI 881), if it were my car, and I were really concerned, I would run one.


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## SentraStyleEMW (Aug 15, 2002)

dmroberson said:


> Just bought and installed a Viper 791XV car alarm with remote start, for my 04 Sentra 1.8S. Question is, anyone know anything about the DEI 508d Proximity Sensor? I'm thinking about getting one and adding it to my car alarm, but not sure if it's worth it. Supposedly it uses radar to monitor movement in and around the vehicle. BTW Ebay has it for about $40, retail is about $90. Any help would be greatly appreciated. Thanks.


The MSRP on the 508D is $90 (but the manufacturer includes install in that price), you can buy the 508D at just about any shop for $50 (normal selling price). I am not a huge fan of prox sensors. They are a pain in the arse to set and more often than not will cause false alarms (especially if you leave any change in the compartment above where you have it mounted or have any type of metallized tint). Pretty easy to install though.


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## Ninety-Nine SE-L (May 5, 2002)

Hmmm, I've never heard of those. It sounds nifty but I an imagine it going off all the time. Unless you park WAAAYYY away from other people, there's just too much normal activity around your car for it to work accurately.


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## dmroberson (Jun 24, 2004)

samo said:


> A proximity sensor uses an electromagnetic field to detect if something enters the perimeter around the vehicle. The best prox sensor on the market is supposed to be Alpine, but DEI makes an excellent one as well. The main use of the prox is to warn approaching individuals that the car is armed. Another use is to scare off the neighborhood cats if you park outside. If the sensitivity is set correctly, they can be very useful. However, 99.99999% are set far too sensitively, and thus false constantly, completely eliminating their usefulness. Although I don't believe in alarms (aside from tracking systems such as Compustar and the DEI 881), if it were my car, and I were really concerned, I would run one.


Thanx for the info, now... how do I adjust it? I had Best Buy install my alarm system, but won't ever let them do anything again cause they messed up my power windows and locks. Want to install the prox sensor myself but not sure how to adjust it. Has 1 knob on it that says Factory Adjust Only, and 2 knobs for Sensitivity.


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## Binger (Aug 29, 2002)

my friend had one in his old beretta. its warning zone was 2 feet away and didn't go off unless you reached in the window.


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