Coil mod

[Guest]

1981 gs 750 dyna-s and green 3 ohm coil,Thinking of doing coil mod.DO I have to do anything to the dyna -s or just wire up relay to coil.Thought I seen where you need to send voltage to dyna-s if you do the coil mod?cant remrmber and cant find it???

[posplayr]

you can try this one.

http://www.thegsresources.com/_forum/showthread.php?t=141055&highlight=coil+relay

[feder1100]

Thanks for fast reply posplayr,I take it my red wire from dyna-s must have 12 volts with switch on.Just not sure where to take it from... the same wire feeding coils after relay or another source??Was just going to get relay and pigtail and keep it as simple as I can,the wiring on the bike is hacked up bad, but works, have not done voltage check yet ,but I would bet this is needed And since I now have started looking into wiring my ingnitor is on but not wired to any thing did the dyna-s take its place just dont know what it did?? thanks KInda new at this

[posplayr]

Thanks for fast reply posplayr,I take it my red wire from dyna-s must have 12 volts with switch on.Just not sure where to take it from... the same wire feeding coils after relay or another source??Was just going to get relay and pigtail and keep it as simple as I can,the wiring on the bike is hacked up bad, but works, have not done voltage check yet ,but I would bet this is needed And since I now have started looking into wiring my ingnitor is on but not wired to any thing did the dyna-s take its place just dont know what it did?? thanks KInda new at this

I would power your entire ignition circuit using the output of the relay. That means Coils and Dyna-S (or the stock ignitor) is all powered from the output of the relay.

I pulled the relay power from Aux (which is fused), but you can wire it anywhere that is close to the battery voltage (using a fuse).

[koolaid_kid]

All the relay needs is a switched 12V power source (orange/white on my bike, I used one going to a coil) and solid 12V battery power (I used the starter relay post). The output of the relay can power both coils and the ignition system (Dyna S in your case). You can keep all your stock wiring in case something fails, and no wires need be cut/removed/slaughtered. The relay is good for (up to) 30A, so other things may also be powered with the relay. Mine also powers my Fiamm horns. When you are done, just make sure the kill switch works, and you are good to go.

[posplayr]

All the relay needs is a switched 12V power source (orange/white on my bike, I used one going to a coil) and solid 12V battery power (I used the starter relay post). The output of the relay can power both coils and the ignition system (Dyna S in your case). You can keep all your stock wiring in case something fails, and no wires need be cut/removed/slaughtered. The relay is good for (up to) 30A, so other things may also be powered with the relay. Mine also powers my Fiamm horns. When you are done, just make sure the kill switch works, and you are good to go.

The relay power needs to be fused to 15amp if you are going to power the entire ignition circuit.

[koolaid_kid]

Of course it should be fused between the +12V and the relay. I used a weatherproof unit with a standard blade fuse of 15A (same as main power). If the fuse should ever blow, I have a spare from the factory in the fuse block cover.
I also covered the other blade connector the the other coil with electrical tape, since it still has 12V when the key is on.

[feder1100]

Thanks for reply,I dont really like the way dyna-s is wired up on this bike, just wrap in tape and I am amazed it has stayed together,The wire were just touching not even twisted.So this is where this wiring job is going to start.So looking into coil relay helped me find another mess, thanks again.

[Steve]

Given your findings, I would first get the Dyna S wired in correctly, then see if you really need to do the relay mod.

.

[chef1366]

Use the O/W wire going to the igniter to power the ignition from the relay(red wire from the Dyna and the coils), cut the O/W wire before the coils but after the kill switch and use that as the switch to the relay. You can hear it click on and off with the kill switch.
OR don't cut your harness and listen to Posplayr.

[feder1100]

thanks again wiring is really a mess and sloppy, but thankfully everything works so just trying to clean it up The wires have been cut, spliced and defferent colored wire every 6 inches in some places its a mess