I've published version 2 of the R1100RT electrical schematic in ladder logic format, with the following improvements:
-added wire colors
-corrected headlight circuit, for both US and UK versions
-improved Key Switch wiring
-corrected functions of Diagnostic Connector


The link above points to the most current version of my drawings for R1100RT, R1150RT, and R1150RT Dual Spark. This link is preferred because direct links to the actual PDFs will someday point to the obsolete drawings if and when new versions are published.

Again, I would be glad to get feedback and corrections.

In particular, I had to do some educated guessing on the headlight circuit. The otherwise excellent Haynes drawings are incomplete on this and I could not get BMW drawings to ensure correctness. I asked UK riders to describe the operation of their R1100 headlight and high beam switches, because US bikes are wired the same way except that the actual headlight switch is jumpered out in USA.

For those interested in the UK headlight details, here is my take on operation, as shown in my drawings:
With Key ON:
Headlight Switch on right grip:
-Off (no lights, other than instrument panel)
-Parking lights (small bulb in front center, aka "Sidelight", aka "Marker", plus taillight)
-Above plus headlight, but either hi or lo beam (not both as in USA), according to the Hi/Lo/Flash switch on left grip

A complication for European R1100 models is that you need to be able to flash the high beam whether or not the main headlight switch is ON.