Please help! 1987 325is with s52 swap from a 91 325i no tach

[PRF3CT]

I have a complete e30 engine swap from my buddies 1991 325i. My car is a 1987 BMW 325is.

I'm having an issue where my RPM tach isn't working now that the swap is complete. Does anyone know what wire I should be looking for to make my tach work?

[mpowerful]

The tach signal is fed to the car via c103/c104 in glovebox im pretty sure. You gotta figure out which pin it would have been on late c101 then route that to the c103/104. Same for speed signal to dme.

[tytypetersen]

Make sure you don't have any blown fuses. My rpms didn't work after my swap and it was a fuse in the fuse box

[NotJesus]

The tach signal is fed to the car via c103/c104 in glovebox im pretty sure. You gotta figure out which pin it would have been on late c101 then route that to the c103/104. Same for speed signal to dme.

Is the same thing true for OBD1?