E21 Rev Counter conected to M50b25 DME

[KriK4eTo]

Hi guys I have problems how to get working the original E21 rev counter with the swaped m50 engine. If someone of you had made this wiring isue please help with the diagram and the changes that i have to make.
Thansk, Veselin

[nas80]

very thin black wire on e21 engine loom goes to black pin 20 on the m50 loom.

If you got the rev counter for a 4 cylinder e21 then it wont work very well.

[KriK4eTo]

The rev counter on the car is for 4 cylinder engine but after I conect the exact wires that you had write down nothing is changing. The counter isn`t working but the strange is that it was working to the last time that the M10 engine was on the car. Thanks any way i`ll try with other counter.

[nas80]

you will need a 6cylinder rev counter. m10 one is not suitable at all as it has wrong ratio for the engine.

make sure you have the correct wires from standard loom. very very thin black wire!

here is mine - my phone is no good at sound, but you get idea. I used 6 cylinder rev counter