Diodes needed?

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=47204
Printed Date: July 05, 2025 at 11:12 AM

Topic: Diodes needed?

Posted By: antol11
Subject: Diodes needed?
Date Posted: January 08, 2005 at 9:38 AM

Hi,

I am installing 4 DEI 805D motion sensors externally on a vehicle (they each have their own enclosures). My question is will I need dioes on the trigger outputs? I have tried to contact DEI but I couldn't get a hold of someone to speak with. Currently I have them wired up to the aux shock sensor input of a Code Alarm 425 alarm unit without diodes and I am having a problem with faulty triggering. For example when if you trigger the first stage warning it will immediately trigger a full alarm even though the full alarm was never triggered.

Also is it ok to power all 4 motion sensors fromt that aux shock sensor input? Or should I power them from a battery wire?

Thanks,

Bogdan

Replies:

Posted By: gcorrea
Date Posted: January 12, 2005 at 1:43 AM

any time you are using two or more sensors you have to diode isolate. do you mean the 508D proximity sensor?

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gcorrea

Posted By: jaurora
Date Posted: January 12, 2005 at 7:27 AM

I hope not. 4 508D's is a little overkill!!

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MECP certified (If it really means anything)
Jeremy

Posted By: misterjimbo
Date Posted: January 12, 2005 at 7:39 AM

it has been my experience with 508 d's that if you power them from the shock port that it gets quite a few false alarms. may i make a recommendation? get your power and ground independantly for each sensor. 4 sensors is a bit much dont you think? to each thier own

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Posted By: Jschult3
Date Posted: January 12, 2005 at 4:34 PM

Yeah 4 sensors is a little much and you should always diode any time 2 triggers are involved.

I think DEI even suggets using 1 trigger from that power source only. Don't quote me though.

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Jeff
Always Verify Wire information before Connecting! Just a Darn Good DIY'R

Posted By: auex
Date Posted: January 12, 2005 at 5:36 PM

You are not supposed to power more then one sensor of the fourpin shock harness plug.

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Certified Security Specialist
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