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  #1  
Old 05-12-2019, 02:26 PM
WingnutWick's Avatar
WingnutWick WingnutWick is offline
 
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Location: Lemoore
Posts: 146
Default No RPM / Tach on EMS after changing setup.

Hello,

So I re-wired the old starter switch to make a push button start with toggle switch for the 1 mag and 1 electronic ignition. The new system works fine as far as starter and magneto/EI functionality goes but now for whatever reason the Tach no longer reads RPM on the E.I. Engine monitor. I've attached a diagram of what I have going on. I believe the two white wires (green in my graphic) are the tach wires. I think there are two because this motor is a H2AD and has the dual combined mag setup and I believe he just combined the two onto one terminal when he put in the EI but I'm not sure.

In any case, I was under the impression from an electrical standpoint that my new wiring setup is exactly the same as the functionality of the original switch. But I'm obviously missing something.

Any help is much appreciated!

Thank you

Charles
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  #2  
Old 05-12-2019, 05:19 PM
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rocketbob rocketbob is offline
 
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Default

If my memory serves on the UBG-16 you had to buy some external modules for tach signals and the inputs they're tied to had to be configured. So first thing is you need to trace the wires. Should work the way you have the connections depicted. If there are two RPM inputs I would use them as intended (one to mag and one to EI) and not tie them together. Suggest you investigate if there are in fact two tach modules installed.
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  #3  
Old 05-12-2019, 07:37 PM
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Default

It does appear that both instrument tach wires are landed to the mag p-lead post. Possibly pull one of those and route to the electronic ignition? Be sure they have isolators/resistors installed.
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Last edited by 10builder : 05-12-2019 at 07:55 PM.
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  #4  
Old 05-14-2019, 09:07 AM
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WingnutWick WingnutWick is offline
 
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Location: Lemoore
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Default

Traced the wires, it looks like they both go to the single tac module. I tried disconnecting them, connecting a line from the EI tach to each and both of them and connecting each of them individually to the p-lead with no luck. I'm curious how it would work fine then just stop working. There is a chance I hit the tach wires to a power source (the one for the starter relay) - perhaps this fried the unit or resistors?

Any thoughts?

Thanks

Charles
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