I've got a wiring diagram from my BMW shop manual, so I don't know how accurate it is for all R65's, or wire colors, but here goes ! On your starter relay connector, there should be a red wire ( a fairly large wire 2.5 sq. mm) and it goes to pin 30 on the relay. This is 12 v from the positive terminal of the battery, this is 'hot ' all the time, that is, power is available all the time. Check this with a voltmeter to see if you have power from the battery. If you don't you need to find the problem with this wire. If you do have power, you need to check for continuity ( low resistance a few ohms or less) in the wire from pin 87 of the starter relay connector to the starter solenoid, it should be a black wire 2.5 sq. mm . My wiring diagram shows that this wire goes through a two pin connector that also has a small blue wire as well. There doesn't seem to be anything else in the circuit that could cause a problem.