I'm finally putting everything back together on my R100, and I seem to have lost track of where one wire goes. There are 2 wires that emerge from the main loom at the same point, are the same length, and have the same female 'flag' terminal on the end. One is brown with a white stripe, the other brown with a black stripe. I'm 99.9% sure the brown with white stripe is for the (single) horn. This is what every wiring diagram I have looked at shows. None show a brown with black stripe wire at all...the horn should be grounding to the frame, but I thought there was a chance the other wire is in fact the ground, and just isn't shown on wiring diagrams for some reason. Here are the two wires: (The red arrows show where they emerge from the loom) Brown with white stripe: Brown with black stripe: So, am I right in that the brown/black wire is the ground for the horn? Are there deviations from the wiring diagrams and what actually made it out into the wild? thanks, Dana
If the 78 had an undertank master like the 77 did... and I'm not sure if it did or not... You might check to see if those aren't the brake light switch leads that plug into the cap of the front master cylinder... That's my only thought.
You're right, it did have an undertank M/C but those are not what these wires are..sorry, I should have mentioned that in my initial post. thanks, though! Dana
Well, I've been looking at wiring diagrams for different years/models and it appears I have the wiring harness from a '79 r100, even though my bike's production date was 9/77. There's a little diode inline with the brake fluid switch that doesn't exist on a '78. I'm thinking my bike had its wiring harness replaced at some point...
I do believe that you will find that the Brown/White is for the horn. The only Brown/Black I know of goes to the Neutral switch. But that one is much to short, unless it comes from the neutral switch and goes to a relay. Time to get out the volt meter and see if you can trace it.
The 78 79 and 80 share the same main harness. some of the 78s and 79s had turn signal beepers in the USA. Most of those were disconnected years ago.
Ah, yes. Forgot about those silly signal beepers. Called my Brother-in-law this morning and had him check his wiring on his 78 R80 and R100. He has a Brown with Black wire going to the buzzer relay, which fires the beeper for the turn signals. He does not have the beeper plugged in. I think that if you don't hook up that Brown with black wire, you will find it will not affect anything else. You could leave it till everything else is connected and then power up the system and turn on the signals, I bet you get power there every time the signal flashes. wirewrkr, thanks for twigging my brain cells about the beeper.
Wasn't the beeper a separate harness the had a two pin black plug or I'm I thinking of something else.
If it is for the buzzer, it's probably good that I didn't connect it to the horn by mistake. Thanks, guys...wiring diagrams can only get me so far, it really helps to have people with decades of knowledge chime in. Dana
It sure as hell makes you remember to cancel the signal . . . or not use them at all. My '79 still has it hooked up, and it's days are numbered.
You could have used it as a backup warning that way. I disconnected mine when new too. In fact, thinking about it, I don't ever remember anyone in the 33 years since that had it on. I would have probably refused to ride with them.
On my '76 100S, the wiring from the neutral switch has a separate, 2 pin black connector at the frame a couple of inches from the switch. Maybe you're thinking of that one?
Before you disconnect it, can you take a couple of pictures of how it was laid out back there. I have lost a bunch of files with wiring layouts that I am trying to reproduce for use on my site to help folks. Thanks
Will do Robert - no problem. Just a note - when the engine drops to idle, there is not enough voltage to trigger the buzzer. So when I am at a full stop, the buzzer is silent. Then when I pull away, it makes noise again and reminds me to turn it off. I have had people turn and look at me as I approached an intersection to find out what the noise was . . . The frequency of the buzzer also varies a bit with engine speed.
