LHB OEM Controls

Left Handlebar Controls

Originally, I intended to create custom left and right handlebar controls. That’s still the plan, but to get the motorcycle up and running quickly, I modified the OEM switches to meet my needs for now. Below is a brief overview of the left-hand handlebar controls.

As always, if you need further clarification or have any questions, reach out.

Wiring

Using the stock wiring, I removed the turn signal running light wires and their power lead, sealing off the wire ends. I didn’t remove them completely from the switch assembly, as they appeared soldered and coated with insulation. Most of the wiring remains OEM, but the horn switch was repurposed as an ECU-switched input, which I plan to use for a two-step function.

For the clutch switch, I extended the leads from the Ducati clutch switch to match the length of the RC51 LH control leads. It’s important to keep the clutch switch leads separate from the LH controls so each can be removed independently.

Since I hadn’t originally planned to use the OEM controls, and didn’t account for the different clutch switch style on the Ducati clutch master, the connectors contain several unused plugs. These will be removed when I build the custom controls, which will include more ECU inputs. For now, this setup is functional.

Ducati Clutch Switch

There may be concern regarding the wire gauge used for the Ducati clutch switch. Approximately 3–4 amps will flow through these wires from the starter relay coil. While 22 AWG wire has a theoretical maximum capacity of 7 amps, bundling and length reduce this. In my case, a safe maximum is about 5 amps.

The run is very short, so I don’t anticipate any issues, but it’s worth noting. If problems arise later, I’ll update this section accordingly.

Turn Signal Logic

As mentioned in the Power Supply section, I planned to use latching switches in the custom LHB controls. Since I’ll eventually replace the OEM controls, I implemented the same logic using the modified OEM switches.

The OEM turn signal switch only allows one position at a time—left or right. Regardless, each turn signal sends 24V back to the power supply, activating the appropriate relay in the fuse and relay box.

Reference Documents