So I bought an 05 Monster S4R with a power commander. The previous owner said when he installed the power commander the speedo stopped working. Has anyone every heard of this and know how it can be corrected without disconnecting the power commander?
PC III or V?
PC III does not interface with the speedo signal, so it would have been coincidence or installation mishap.
No idea on PC V.
PC v doesn't either. I've installed both PC III and PC v and you're nowhere near the speedo
It's a PC3.
Is it possible to check the rotor sensor without taking the rear wheel off? I don't have a stand so I'd have to have someone do it for me unfortunately.
There is no clearance spec that I know of for that sensor, although clearance is important in as much as it needs to be close enough to read but not close enough to hit. Since no shims seem to be available if no modifications were done (like non ferrous rotor bolts) all should be good there. The sensor is in the caliper bracket. It is a Hall sensor, three wires. Red/blue wire is positive, middle (green/gray) is output and black/ violet id ground. As the rotor bolts pass the hall sensor you should read a 12 volt on/off signal from the sensor.