Light Speed RPM Connections

I'm trying to hook up dual Plasma III systems to my AFS 3500 which formally had a Slick mag pickup with three wires (as detailed on the wiring diagram of the installation manual. Light Speed says that the RPM signal is on pins 6 and 13. But how do you connect two wires to three?

Shawn McGinnis pointed me to page 188 of manual v3.0 which is the same as above and doesn't help me. Also offered was the purchase of a 71420L, but I can't find any information on pricing or description on the web site.

Help appreciated!!

John Templeton

You don't connect it to any of the three wires. The Lightspeed outputs the rpm on pin 6 and that needs to wire to the engine board pin 33. You can only wire it to one of the Lightspeeds unless you get our RPM interface board.

There is a good chance that your ems board is the old rev and will need to be updated or need the interface board to work.

Thanks Rob -

How can I order the interface board? So only one wire - off of pin 6 on the LS?

Call Tricia in sales

Quick follow-up question on this thread... so on an EFII Dual Ignition System, what is the preferred set up:
1) Monitor RPM from a single ECU RPM Sensor output to pin 33 (and ignore the other ECU)
or
2) Install the RPM Interface with connections to pins 31, 32, 16... assume this creates some redundancy?

Connecting both electronic and sensor inputs will create all kinds of unwanted noise.

Hi Shawn... working with a dual electronic ignition (EFII is the manufacturer). Just needing some direction on best set up for RPM input into the EFIS. Thanks,

Call Tricia and order a dual electronic rpm board. That will let you switch and see both.

I have the same set up... dual EFII going into the AFS RPM board and the tach will go to zero below 1000 RPM. the output amplitude of the tach signal goes down at this threshold. Robert at Protek EFII confirmed this. I'm not sure what needs to be done to fix it to show the RPM below 1000 now.

Quote:

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Originally Posted by Shawn McGinnis

Call Tricia and order a dual electronic rpm board. That will let you switch and see both.

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Rob, Shawn:

What is the solution for this issue?

Thanks,