M60 Tach Signal Help - 85 325e

[ArtFoodBMW]

I can't get my tachometer to work for the life of me.

I have my tach signal noted as coming from Pin 14 from the X20 (Black and white wire)

Connecting it to Pin 1 of the c104 is showing no response.

My tach worked with its previous heart, and I tested with a different SI board showing no change.

Anyone have any ideas?

[jpod999]

Are you using either a Dakota or the garagistic module wired in between the motor and the cluster?

[ArtFoodBMW]

Are you using either a Dakota or the garagistic module wired in between the motor and the cluster?

I'm using the garagistic coding chip that replaces the normal 4cyl or 6cyl chip in the cluster. I should also note that switching that chip with an OEM one shows no change in tach performance.

[sweet3]

Double check your pinout. I'm assuming you made your own adapter, right?

[36brua]

Hi my car is an 86 pin out is

X20 14 blk/white vehicle speed sensor vss. C101 14 added a pin and wired to yellow connector on cluster

X20 20 blk TACH. TO C104 connector

C104 to back of cluster blue terminal
I wired the earlier garagistic 'doubler' in between c104 and tach with m 42 coding plug . I think the Dakota digital is an option

[ArtFoodBMW]

Figured it out.

I was using pin 14, should have been using pin 20.

My ETM for the engine harness claimed pin 14 was tachometer. But comparing other wiring guides (like m50 x20 outputs) the black wire from pin 20 is the tach signal.

Further reason this makes sense: all wires on the e30 for tach signal are black.. which lines up with the also black x20 tach signal wire...