Fitting an OEM Pod Tachometer to my 1990 R100GS

[Jono123]

Hi all,

I have bought an OEM Tacho which is in a pod and fits to the right of the instrument panel but it didn't have any fitting instructions - does anyone know how to fit one?

Keen to know which wire goes where, I am assumin red is +ive and black -Ive and the yellow is the trigger wire - keen to knwo where the trigger wire goes, is it to the coil or is it inductive i.e. does it jus lie along the HT lead?

Any help greatly appreciated

[Rob Frankham]

I believe there should be a connecting block somewhere and the OEM tacho should just plug in...

Rob

[gspd]

The red/black/yellow tach wires are not OE from BMW.

Trigger goes to coil negative terminal.
There should be a BLACK wire in the OE dash harness for this.

Be sure the tach only has power when the ignition is 'on' or it will drain the battery when the bike is parked for extended periods. (look for GRN/BLK wire).

Ground is any solid BROWN.

[Rob Frankham]

I have to say that I agree with GSPD on this, a OEM BMW unit would normally have wires coloured Green (or Green/Black) - 12 v, Brown - Ground and (probably) Black -trigger. I have to question, therefore, whether what you have is truly OEM. Can you give a bit more information (or pehaps photos) of the unit.

If the Tacho is second hand or not BMW packaged, be very sure you identify the connections and don't assume that it is designed to connect to the coil. There are various types of circuitry used in tachos depending on application and connecting your unit wrongly may destroy it...

Rob