Hey,

I installed a om601 2.0D engine to (originally) c220 2.2 petrol car.
Everything is fine now, but the only thing not working is the tachometer doesnt show rpm. I have the diesel instrument cluster, rpm sensor and the relay witch should make the signal from the crank sensor understandable to the instrument cluster.

What I dont have is the wiring diagram. The relay has KARA written on it (and the merc code ofcourse)

There are pins that have names written near: GM+ and GM- , 31, 15, AR+ , TD, and DI.

As I understand 31 is the ground, 15 should be +12v, but what the others are?
Could someone help?

Thank you for your help.