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Discussion Starter · #1 ·
Hey fellas,
I have a 82 gs1100e that im finally starting to work on aesthetics, and i need to hook up some gauges. I have a set of gauges from a 1990 katana 750 that im trying to wire in. Im on top of the speedo, but the tach is frustrating the hell out of me.

My gs has two ign coils both with constant 12v and are triggered on the negative side from the ign module.

My katana gauge has three wires, 12v, ground, and signal. Unfortunately the 90 katana gets a signal from its' ign module(12v). So i need to get a 12v trigger like signal to the gauge.

I had it wired up on a coil such that both constant 12v and 12v signal were wired to the (+) battery and just the ground wire on the negative side of the coil, but this arrangement will ground out the ignition coil, causing me to lose two cylinders. This arrangement does give me correct rpm reading though.

I have tried a diode on the negative wire coming into the tach and it does not do anything, intuitively it shouldnt, but just a try anyway.

Maybe im missing something really simple, but im just testing the waters to see if any other peeps have encounter something like this; maybe you can help.

Thanks
 

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You could use a transistor across one of the coils to get this, when the coil is triggered by grounding out the other side, this can be used to ground out a transistor, supplying power to your tacho.
 

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Discussion Starter · #3 ·
Thanks for the reply. I'll have to read up on how transistors work as I'm pretty inexperienced with circuits. I do have a few of them, do u have a size or form factor you recommend?
 

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Discussion Starter · #4 ·
Should I wire it up so the pos terminal of the ign coil is wired to the emitter and tach signal to collector and the negative on the ign coil to the base? And use this with a PNP transistor?
 

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Discussion Starter · #5 ·
Nvm. I got it. I tried every single wire coming out of the ign module and one worked. Yeaaah boi! Thanks for your help though, I'm sure it would have worked with the transistor.
 
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