Rewiring 101 with the Motogadget M-Unit

In our first guest blog, customer and bike restorer Chris Burkhart explains installation of the Motogadget M-Unit to fix a wiring fault in his BMW R100RT and installing the M-Lock hands free ignition lock.  

M-Unit

Ready to Rewire

 Instead of fussing around with the old wiring loom. I decided to rewire with the Motogadget M-unit and M-lock.

After reading the documentation I fabricated a mounting bracket to put the M-unit under the seat. I should turn the M-unit around which would place the positive lead almost on to of the battery terminal, but I prefer to have a short length of cable available to absorb vibration and allow the M-unit to be placed for easier reading.

I checked the resistance from the earth terminal shown at the back of the terminal block, the M-unit and the mount to the chassis ground wire (seen to the right of the batter). With my multimeter’s Ohm scale set to 200, I had a reading flickering between 0.2 and 0.3. I’m calling it 0.25 ohms. The reading from BMW earth point at the Voltage regulator is a solid 0.3. I’m accepting the grounding as solid.

Pictured is the M-unit and also a good connector block this block accepts 1/4” female connectors in groups of four. I will be using one group for switched positive (Aux output), one group for un-switched positive, one for earth, and the last as a spare if any of the previous groups need more terminal.

This job took about 3 hours so far. The bulk of the time involved unwrapping BWM’s wiring loom and separating old circuit in preparation of the new wiring. What a mess. I could see many areas that were ready to go out. I especially liked the way BMW would swage wires together within the wiring loom making it difficult to chase down faults. But then they would have you buy an entirely new loom to fix one sub 22 gauge wire break.

Next up, Install the M-Lock and Configure the M-unit.

~Chris Burkhardt