BMW R1200RT/R1250RT Forum

I just bought a used 2007 R1200RT-P former police bike with 57K miles and no warranty. I have found that the directional signal is somehow (intermittently) tripping the rear lights to display emergency flashers - that is, sometimes (not always) when I use a turn signal, both rear lights flash in unison as if the emergency flashers were turned on. Oddly, the panel only displays a turn signal, even though the rear lights themselves are both flashing. I assume it is a faulty switch somewhere, or perhaps a loose wire or something that may have been caused when they disconnected the police lights after it was auctioned off for civilian use.

First: I know almost nothing about maintenance on a bike like this and have very little knowledge or skill with electrical stuff. But it is also a real pain dropping the bike off at a BMW dealership because I don't have a ride and would have to wait in a waiting room while they repaired it. And if a part needed to be ordered, I could be stranded there or have to make ANOTHER trip back and wait again.

Is there any way to diagnose this before going to the dealership? Can a new switch be pre-ordered? Is the switch hard to get at and replace? If anyone knows anything about this, I'd sure appreciate any advice or suggestions.

Think we have been here before.
Either you have a defective switch which is  unusual on your age of  bike or
As you suggest someone who has removed the police bits has damaged something.
The bike has canbus wiring and doesn't take kindly to being interfered with.
Independent garages can do more harm than good if they are not familiar with the  system.  You could try removing the back light and check all the connection on it have no corrosion. If the front indicators work properly it might just be a fault in the back one.  Short of that I think you have no option but to ring a dealer.

I don't know much (anything) about Canbus, but the symptoms could indicate a bad earth for the indicator lights, so the earth goes through the other one causing it to flash too.