4 sensors to alarm single port?

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=143763
Printed Date: June 04, 2024 at 6:14 PM

Topic: 4 sensors to alarm single port?

Posted By: couch_c
Subject: 4 sensors to alarm single port?
Date Posted: November 12, 2017 at 4:53 PM

So I've wired my alarm several years ago with 3 sensors with diodes all to one port. Now looking at it, I want to add one more sensor but I don't think the one alarm port has enough power to power all 4 sensors so I was wondering If I should use a relay.

I want to use 2 504d shock sensors, a 508d proximity sensor, and a 507m tilt sensor. I've seen the manual where it has a diagram where I can wire the shock sensor with the proximity sensor without having to use a diode but I feel like it'd be probably easier to wire them all separate since I have 4 sensors.

I can't remember exactly which direction the diode band go, it's been a while since I've wired anything so please take a look at my (not so good) diagram. I'm a little confused at some parts like the "arm when ground" wire coming off the alarm. I'm not sure what to do with it, should it go to the relay or should I just wire all 4 sensors grounds straight to it? Also I'm not sure if 85 and 86 on the relay should be switched. Thanks in advance.

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Replies:

Posted By: howie ll
Date Posted: November 16, 2017 at 11:09 AM

The above diagram has the diodes shown correctly, band away from alarm/RS
Don't use the relay, it will drain your battery.
Use the alarm/RS power supply with a separate 3amp fuse.

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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.

Posted By: couch_c
Date Posted: November 17, 2017 at 9:09 PM

Thank you for the reply I appreciate the help. I do have a question about the relay though. I've always thought that it doesn't supply or drain battery as long as it's not switched on, or does it constantly drain no matter what?

I'm not too sure what you mean by rs? As in remote start? Right now I'm trying to figure out if I should just wire all of them to the same power source as the main harness and fuse them all like you've said. I just hope they don't all drain the battery or I guess I could wire them to the GWA orange wire.

I've ran 3 sensors previously off of the sensor port power wire but I'm not too sure if the wire is enough to power all 4 sensors. I've checked with a multimeter and only read 11ish volts coming out from the alarm. Funny thing is, it'll power one sensor I know that for sure but when I tried to use it for the relay couple days ago and it didn't have enough volts to switch it on.

Posted By: howie ll
Date Posted: November 18, 2017 at 3:27 AM

You can round 85 through either GWA (ground while armed) or direct ground, either way there's a constant c. 110 miliamp draw across 85 and 86.
86 of course to a constant 12V+
That means that with GWA that relay is drawing whilst the alarm is on, R/Start with an alarm the same.
Just give them constant power and ground, the 507M via the GWA (orange).
One last thing,good luck with all the false alarms you're going to get.

-------------
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.