"78 R100S Ignition Switch

Put in a new ignition switch. Trying to reattach wires using wiring diagrams. Of course two sets of drawings contradict each other.

Switch has 4 vertical terminals and one horizontal. I currently have a double green wire on the first lug, gray on second (working toward back of bike), red on third and green on last one. No wire attached to horizontal terminal.

Bike runs fine and all lights work properly with this combo, but I seem to have a drain on the battery much stronger than just the clock.

Please help me get this right. (Wiring diagrams from Clymer and Chitek.

Thanks,

Bob

Not sure about your "first one, second one, etc.". But my Haynes has a double green on #56 (my first one on the left in the diagram), a gray one on #58 (second one), a green one on #50 (my third one), and a red wire on #30 (my fourth one, the last one on the right).

Our descriptions have the last two reversed.

first part of diagram

this,

plus this

look at (f) and the color code on message before this. Diagram is from factory BMW service manual for 78S.

Thanks for your replies. I switched a couple of wires and crap, the starter didn't work.

Switched the wires (red and green) another way and hold and behold everything seemed to work more or less properly.

By more or less properly, I think dash lights and tail light should illuminate in the park position, but this has never happened on this bike.

At any rate, went for test ride and all is well. Everything worked. Thanks again for your help.

Aren't there terminal numbers molded on to the switch?

There may be numbers in there but my old eyes aren't able to see them and I'm not inclined to pull the switch back out for a closer look.

I have had the fairing on and off so many times lately............

Our descriptions have the last two reversed.

Click to expand...

My ignition switch has terminals coded 15 on one end, 58 on the other end, 56 on the diagonal terminal and 30 marked between the middle two. It is a '78 R100S.