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DEI 451m relay question

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=33869
Printed Date: August 25, 2025 at 12:08 PM


Topic: DEI 451m relay question

Posted By: MBZ oe
Subject: DEI 451m relay question
Date Posted: June 14, 2004 at 4:13 PM

I am installing a clifford matrix rs 3.5 in my 87 300E benz and need some advice about the 451m relay pack that is included with alarm system.

The back of the 451M relay says: 3pin plug- green (-) lock input, red (+)pos input for coils, blue (-) unlock input. I know where this plug goes.

The 5 wire harness is labeled:

purp/bk lock/unlock normally open #87

grn/bk   lock output#30

wht/bk   lock normally closed #87a

blue/bk  unlock output #30

BROWN / bk unlock normally closed #87a

 Here is what someone else told me to do, but why does the purp/bk have an inline fuse? And there is a purp wire coming out of relay that joins the purp/bk at the in line fuse :

GREEN/ black and BROWN / black are tied together(lock relay 30, unlock relay 87a)

WHITE/ black goes to the switch side(lock relay 87a)

blue/black goes to the motor side(unlock relay 30)

purple goes to 12v(unlock relay 87)

PURPLE / black goes to ground(lock relay 87)

So, if the PURPLE / back is to go to ground, why does it have an inline 15amp fuse?

TIA for any help



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BOOM, BOOM, BOOM BOOM....



Replies:

Posted By: auex
Date Posted: June 14, 2004 at 6:40 PM
Ok this is how you do it. You need to cut the lock/unlock switch wire. Then wire the switch end of that wire to the WHITE/ black. Wire the pump side to the blue/black wire. Then wire the BROWN / black to the GREEN/ black on the 451M. Then wire the violet/black to ground and violet to +12V constant. You have to cut the fuse off of the purple wires but I would recommend that you replace it on both, just because it is going to ground doesn't mean that there isn't any current going through it. Basically you are wiring the 451M like these relays.

posted_image

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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.




Posted By: MBZ oe
Date Posted: June 14, 2004 at 6:54 PM

The violet and the violet/black both exit the relay seperately then are connected into an inline fuse together before/at the fuse. So you are saying to cut the violet away from the violet/black, and hook the violet/black to ground? And the violet to 12v. Right? The small red wire of the 3 prong plug says 12v+ input for relay coils as well. 

 I just want to make sure before I cut. I understand how to connect it to the pump system.



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BOOM, BOOM, BOOM BOOM....




Posted By: MBZ oe
Date Posted: June 14, 2004 at 7:04 PM
Okay. I am slow with this and I just noticed that you did say to cut the fuse and add another to the ground as well. So the Violet/bk is the 87 to ground, and the violet is the 87 to 12v, and the small green and small blue would be the 85 and 86 in the above diagram. Correct right?

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BOOM, BOOM, BOOM BOOM....




Posted By: auex
Date Posted: June 14, 2004 at 7:20 PM
Do not cut the small three pin harness, just plug it into your alarm. Violet is +12V and violet/black is ground. The small red wire in the 3 pin plug is only powerful enough to trigger the relays not to activate the pump. I didn't mention any of the trigger's I posted above for a reason, 85 or 86 on the diagram, they plug directly into the alarm by way of the three pin plug.

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




Posted By: MBZ oe
Date Posted: June 14, 2004 at 8:06 PM

Thanks for confirming and helping me understand this. I am a DIY'er and will be looking for some install books to read so I can better understand.

Best!



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BOOM, BOOM, BOOM BOOM....




Posted By: mignacio
Date Posted: June 16, 2004 at 4:33 PM

Can someone help me. I too have an 87 300E and I also used a 451M relay but I have mine hooked up with a Rattler 369D. However I do not believe that the 369D can be set to have a longer than 1 second pulse to unlock the doors. This results in the vacuum pump activitating to lock the doors for 1 second and then all of a sudden it unlocks the doors. I heard that if the 369D does not have a 3sec or longer door pulse than I can get a timer. I was looking at the DEI 528T but I'm not sure exactly what I'm supposed to do with the timer.

Thanks
Mike





Posted By: MBZ oe
Date Posted: June 16, 2004 at 4:59 PM

I don't know about the rattler alarm, but wanted to let everyone know that the install was a success!

I am very satisfied with the Clifford Matrix RS3.5



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BOOM, BOOM, BOOM BOOM....





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