tachometer wont wrok

[polarise30]

so my e30 m50 swap has been running for a while but my tach has nbot worked sence i have dont the swap and i really would like one so if some one could let me kn ow hot to hook it up that would be great thank you

[MrEricT]

What year is your e30??? You may have to hook it up to the c104 connection in the glove box. Going from my memory its pin 9 in the c101. Should be a solid black wire. Run that to the green wire on the flat white connector in your glove box. Not the middle green wire as this used to power your ecu which you no longer need, its the one on the side. The yellow or yellow/white wire on the other side is for the econometer.... if you wanna hook that up.. get that signal from c101 pin 8 and tie it in here.