starter button relay.

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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=93479
Printed Date: June 10, 2024 at 10:21 PM

Topic: starter button relay.

Posted By: 12v nut
Subject: starter button relay.
Date Posted: April 30, 2007 at 3:22 PM

HI all!

I've just completed a starter button mod in my 2002 E47 M3.

I used the Honda switch from an S200, looks great!

trouble is when the ignition is on (driving) its possible to accidentaly press the button and its still active, is there a way to wire a relay to make the button inactive while the engine is running by possibly adding a second relay?

My wiring is........12v swiched live to pin 30, wire out to starter, pin 87,push button switch ,pin 86, ground and button ground to pin 85.

Thanks guys.

Replies:

Posted By: dualsport
Date Posted: April 30, 2007 at 11:59 PM

Probably other ways to do it, but here's one way to do it-
posted_image

If you try this, you need an added connection to the starter terminal or relay (you can use the connection from your existing relay going to the starter), which is used by the circuit to act as a ground for the relay coil. This way, the bottom relay latches on only after you release the starter button, opening up the connection for your starter button, and preventing you from hitting it a second time. Turning off the ignition resets it and allows you to crank again.

Posted By: 12v nut
Date Posted: May 01, 2007 at 2:55 PM

Thanks, will give this a try.

Posted By: hotwaterwizard
Date Posted: May 01, 2007 at 9:13 PM

What kind of voltage Regulator do you have on your Engine?

On a Hot Water Pressure washer we just tap into the wires of the coil before it goes to the Regulator.

Then hook a Bridge Rectifier across the wires and use a 24vdc relay to allow the burner to come on only when the Engine is running.

We could use the same relay to prevent something from comming on by swapping one pin on the relay.

posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: May 02, 2007 at 8:39 AM

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: 12v nut
Date Posted: May 02, 2007 at 1:32 PM

hanks, but a little technical for me posted_image

I found this posted_image

Look OK?

Posted By: hotwaterwizard
Date Posted: May 02, 2007 at 8:26 PM

I rearanged the wires so it would be easier to understand. I have another Idea I am working on it would be better to wait before you do any wiring.

posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: dualsport
Date Posted: May 02, 2007 at 8:48 PM

That's much easier to read, but I still don't know what that circuit is supposed to do- relay #1 is used as a starter relay, and relay #2 opens up the connection between Ignition & BLACK / YELLOW wire while cranking only. Only use I can figure for it would be to open up power to accessories during cranking; is that the idea?

Bunch of questions-
Why is there a 20A fuse for the coil of the No. 2 relay? Unless that's one humongous relay, all it needs is a fraction of an amp. (?)
What is the pushbutton doing with the ground connection? 5A power from the IG ON/START +12V?

Posted By: hotwaterwizard
Date Posted: May 02, 2007 at 11:02 PM

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: May 02, 2007 at 11:16 PM

When the Alternator is putting out power it turns on the relay the normally closed contact opens and stops the power to the switch.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: 12v nut
Date Posted: May 03, 2007 at 8:39 AM

posted_image

Tried this on the bench and it seems ok,look right?

Posted By: hotwaterwizard
Date Posted: May 03, 2007 at 8:53 AM

Will look when I have more time. On the bench is not the same as in the car The relay is it 24v?

posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: 12v nut
Date Posted: May 04, 2007 at 8:32 AM

Thanks...relay is 12v.

Posted By: hotwaterwizard
Date Posted: May 04, 2007 at 8:52 AM

I Know this sounds stupid but, Why does the button have 3 wires?

Com Norm open Norm Closed?

Pinout of the actual switch would help

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: 12v nut
Date Posted: May 09, 2007 at 1:29 AM

Wires are, signal, power in and ground.

Posted By: hotwaterwizard
Date Posted: May 09, 2007 at 7:42 AM

Ok it is a lighted switch? Why the extra ground?

For AC I understand why you use an extra ground ite is to shield the switch and provide a ground path for stray ac voltage so you don't get shocked. But in a DC circuit it is used as a referance or to provide a ground for a light.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: May 09, 2007 at 8:00 AM

I would draw it different so you can see the contacts of the switch.

posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: endeffect
Date Posted: May 11, 2007 at 3:18 PM

you dont need the ground wire for the switch

Posted By: hotwaterwizard
Date Posted: May 11, 2007 at 8:42 PM

The only reason you may need a ground is to prevent False starts from static electricity.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: 12v nut
Date Posted: May 18, 2007 at 5:54 PM

The ground is for the switch illumination.

Posted By: hotwaterwizard
Date Posted: May 18, 2007 at 8:35 PM

How about this one?

posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

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