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Discussion Starter · #1 ·
This is the diagram from My427sc.com and it shows a diode between the "S" position on the dimmer switch relay and the "85" on the "flash to pass" relay. With the flow of the relay going downward, as the diagram shows, won't it prevent the ground signal from going up from the button on the turn signal stalk to the dimmer switch relay and thus make the dimmer switch relay inoperable? I am just giving this some thought before I wire in the diode or test it. Am I not fully understanding something here?



Thanks!
 

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Discussion Starter · #2 ·
Essentially the wire from the "S" on the dimmer switch relay post to the diode (circle with the arrow in it) is shut off because of the flow of the diode right? How does the signal get to the "S" on the dimmer switch relay then if it won't flow past the diode? :(

Just thought I'd clarify my original post.

Im fully confused.
 

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Ted,
I am not sure of all the details, but I wired mine exactly per that schematic and everything works perfectly. I installed the relay and wiring Saturday in a couple of hours.
Tony
 

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Discussion Starter · #5 ·
Further down the circut shows the black line is the button toggle on the end of the turn signal switch that controlls the hi/lo beams. The dimmer switch relay needs to be activated by the button which is the black wire that is shown on the diagram. It is a ground activated relay so the "S" onthe dimmer switch relay is a needed ground....but with the diode there it can't get the ground feed from the button, right? The relay is getting plenty of 12 volt power, but no ground.
Here is the bottom portion...
 

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Discussion Starter · #6 ·
Tony,

It all works? I am just cinfused how it can work with that diode there. Can somebody please explain how the top relay gets its "ground" with the diode there?

I'm going out to wire it now.

Thanks!
 

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Discussion Starter · #7 ·
Tony,

It all works? I am just confused how it can work with that diode there. Can somebody please explain how the top relay gets its "ground" with the diode there and thus not allowing flow to the "S" terminal?

I'm going out to wire it now.

Thanks!
 

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FFCobra Craftsman
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Power from terminal #30 of the top relay flows through the coil to terminal "S". Any ground applied to the black wire will then complete the circuit and cause the relay contact to move. With the diode installed as shown, power can flow from "S", through the diode, to ground when the switch on the t/s stalk is pressed. If you were to remove the diode the flash-to-pass relay coil would get a constant ground through the contact in the dimmer relay and then through the low beam filament of the headlights.
 

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The diode isolates the grounds on the two relays. The ground path is provided by the closure of the upper contacts on the “Turn Signal” switch…
 

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Discussion Starter · #10 ·
OK, thanks for the lesson on electrical 101. I was thinking that the ground traveled to the "S" terminal. Never thought it could go the other way. I am definitely not an electrical person.

Thanks for the help guys!
 

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Look closely at the flash to pass relay on the drawing. 86 and 87 are reversed . It won't make any difference if you wire it the way shown. 86 is a coil terminal and 87 is the N/O on the relay.
Just getting picky.
 

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I belive the "flash to pass" relay would back feed into the dimmer switch relay causing the headlights to always be on when only the lights are activated. I think this would happen because the coil on the relay will take current flowing in either direction. So if there is a load on the other side of that yellow wire coming out of the flash to pass relay it would activate whatever that load is...
 

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Discussion Starter · #13 ·
Wired it up and took it for a spin tonight. Works great!

Thanks guys for your help.

BTW, I did not put the diode between the 2 relays. What happens now is that if I use the "flash to pass" switch it will kick the high beams on the next time I turn on the headlight switch. No biggie. Just have to flip them back to low beams.


Works like a champ!

Ted
 

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Ted, there is no such thing as a "ground signal".

The diode is correctly wired to pass current through it to ground... current flows from a higher voltage to a lower voltage (ground).
 
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