Rev counter connection from Omex ECU

[Mikey UC]

Rev counter connection

Normally the rev counter is connected to the –ive side of the coil (on cars without an ecu)

The Omex ecu has a rev counter output that connects on to –ive coil lead (which is no longer being used as a coil pack is replacing the coil )

Only thing is the –ive coil lead has a voltage of about 3.5 volts, so I was a bit wary about connecting the ecu onto it.  I contacted Northampton motorsport just to check the connections and they confirmed the rev counter lead connects to the coil –ive lead but was unsure about the voltage that I was measuring.

Just wanted to check I am not about to fry my ecu by putting a current down the rev counter output.

Anyone installed an Omex could help on the rev counter connection ?

Many thanks

 

Mike

[keybaud]

Which ECU is it? My Omex 600 rev counter output (blue/yellow wire) is the signal wire to the rev counter, which also has a positive and a negative feed. The ECU gets the RPM from the crank sensor.

Page 25 has more details and discusses the coil positive and negative confusion.

http://omextechnology.co.uk/600%20ECU%20Installation%20Manual%202v01.pdf

[Mikey UC]

Thanks keybaud

I have the Omex 200 with a blue/yellow wire from the ecu to the tacho and page 25 is exactly the same in my manual.

My car is one of the older versions not having an ecu where the tacho was driven off the coil -ive lead. So i was just going to connect the blue/yellow wire into the now redundant coil -ive lead.

it's just that i wasnt expecting a +ive voltage on this cable when measured with just the ignition on.

Hmmm