G'day all, well I got myself a 2 pin diesel tach from the USA, i also got a tach amp

the engine i got is om617A and it has the pickup on the front of the engine

the pickup wire is installed, the tach amp is in place

I'm just having trouble wiring it.


I tried following this guide. ( see attached picture )


i used a multimeter to see which wire was which, the green + yellow wire is number 3, however i'm struggling to find where it's supposed to go in the wiring loom

I can't find the correstonpding enf to connect it to.

the car has the tach plug behind the instument cluster, but for the life of me i can't find the other end, i tried tracing it, but it goes into a 2 inch thick loom of so many wires under the dashboard and from there i lose it :/

with the connecting wire behind the dash
I see the + is for straight 12v( black + red stripe ) , and the other straight black ) is for signal. But no luck, i tried running a wire straight from the number 3 output from the tach amp to it, and no go :'(

the car

1985 280CE ( manufactured in 1985 ) with om617A engine transplanted into it. I'll grab some pictures


off of the tach amp i have these wires.

+ 1 more for power.

i have

1x brown = ground
1x red = +12V ?
1x black + red = unknown
1x green = unknown
1x green + yellow = signal to tach.

Attached Thumbnails