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Central Door Lock Switch to 451M Relay

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=142885
Printed Date: March 28, 2024 at 8:04 AM


Topic: Central Door Lock Switch to 451M Relay

Posted By: kjd186
Subject: Central Door Lock Switch to 451M Relay
Date Posted: April 20, 2017 at 11:52 AM

Need help connecting 1 central power door lock switch (3 wire) to 451M relay.

For 2007 Jeep Wrangler 4-door with aftermarket 2 wire door actuators. All doors lock and unlock with Karr Security System remote.

3 connections from switch are (1) ground and (2) blue of the 451M relay(3 pin connector) and (3) green of the 451M relay (3 pin connector). 3 pin connector cut off and only blue and green wires from 451M relay used.

Switch will only unlock. Reversed blue and green connections and nothing happens. Removed ground and connected to power, relay fuse blown and seized left side door actuators (ouch).

What connections do I need to make to get the switch to both unlock and lock the doors? Additional relays? Thanks.



Replies:

Posted By: kreg357
Date Posted: April 21, 2017 at 7:47 AM
Think the Red wire from the 451M in that harness that has 3 wires ( Red, Blue & Green ) that you cut off needs to have +12V constant.

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Soldering is fun!




Posted By: kjd186
Date Posted: April 21, 2017 at 8:23 AM
3 prong plug (I previously said it wrong) - blue and green wires actually go to alarm brain unlock and lock wires. Red is connected to power. I can't figure out why the switch won't lock.

Other connections from 451M relay
1)     Purple/Black wire to 12V power
2)     Green/Black wire to actuator green wire
3)     Blue/Black wire to actuator blue wire
4)     White/Black to ground
5)     Brown/Black to ground

Thanks.




Posted By: kreg357
Date Posted: April 21, 2017 at 8:48 AM
I'm confused.

It would seem to me that the Karr Security system is already controlling the door lock solenoids. How is it doing this? Does it have built in relays and wires going to the added door lock solenoids? And then you are adding on a 451M module with a central locking switch?

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Soldering is fun!




Posted By: kjd186
Date Posted: April 21, 2017 at 9:18 AM
When I got the vehicle, it didn't have any door actuators - all manual. The Karr Security System was already installed - 1 relay wired to it already. I assumed it was for some other part of the security system. I found the unlock and lock wires on the Karr Security System and connected a 451M relay to it. I guess I now have 3 relays - 1 originally there and 2 from the 451M. I installed the 451M relay for the newly installed aftermarket door lock actuators and it works fine, but when connecting the 3 wire switch, it won't unlock. Now that I think about it, I think I have two wires on the switch connected wrong. I had them on the blue and green of the door actuators which connects to Green/Black and Blue/Black of the 451M relay. The switch is actually not connected to the 3 pin connector. I probably need to connect the switch to the blue and green of the 3 pin connector which connects to the lock and unlock wires of the alarm brain. Possibly?

Thanks.




Posted By: kreg357
Date Posted: April 21, 2017 at 9:41 AM
I would guess the one relay with the Karr system is for a "starter kill" or perhaps the parking lights. If you added the door locks and the 451M module and it works under the control of the Karr system, you should be able to add the new central lock switch to those Green and Blue wires that go between the 451M and the Karr unit ( 3 pin harness with Red +12V wire ). To protect the Karr unit, you might need to add diodes between the switch connection point and the Karr unit so that the switch input ground does not get to the Karr brain.

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Soldering is fun!




Posted By: kjd186
Date Posted: April 21, 2017 at 10:54 AM
Thanks. How do I know if I need to add the 2 diodes, which diodes to use (have a bunch that came with 451M relay), and which direction do the diodes go?




Posted By: kreg357
Date Posted: April 21, 2017 at 1:12 PM
Usually it's just resistors that come with the 451M module. I use 1N4001 diodes for that application although higher rated diodes like the 1N4004, 1N4007 will work fine. You really don't know if you need them without having the schematics of the Karr unit ( and having an EE degree posted_image ). Sometimes applying a ground ( or 12V ) to an output type wire of an aftermarket unit can cause problems. The diodes would allow the Karr to control the 451M as it does now but prevent the ground signal from the switch from getting back to the Karr unit. At the same time, using the same wire, the new switch could control the 451M. Diagram below ( diodes bands towards the Karr unit ) :

posted_image

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Soldering is fun!




Posted By: kjd186
Date Posted: April 21, 2017 at 1:22 PM
Thank you so much. I will give it a try this weekend.





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