Re: Wiring discussion

[Wayne Woodruff <wayne@xxxxxxxx>]

On Sun, 12 Feb 2006 18:45:50 -0800 (PST), you wrote:

>I've been doing some dissecting on a defunct wire harness. My first quite successful project was to cancel out the safety disconnect for my side-stand and rewire to the horn. Now if there is a failure with the wiring/switches/relays associated with the side-stand "alarm", the bike will not be stuck on the side of the road. 
>   
>  I did some more dissecting and learned there are a whole bunch of wires running all through the bike... wires that can break.... connections buried, rapped in tape in inaccessible places. Why run wires all through a bike when you can ground to the bike, right on the spot? Wires break, so why wrap so many together? Doing so confuses the issue further when you have to find a problem. My fuel injectors have a ground wire that travel deep into a mess of wires wrapped in tape, only to end up grounding to the bike somewhere waaaaay down the line.
>   
>  Why not ground these wires right near the injectors? Placing the ground to the bike, near the injectors, places a potential  bad ground in a logical place, in plane view. What am I missing? I'm ready to cut all these particular "green w/yellow stripe" wires which wind all over the bike and are all associated with the side-stand, clutch, and kill switch safety disconnects. I could ground various relays in the fuse box associated with these looooong wires running everywhere. The fuel injectors. The kill switch can remain by grounding right at the switch. Comments, suggestions?
>

Doug,

As you add grounding points, you run the risk that one of them will
develop a high resistance.  This will lead to ground loops, which are
a BITCH to troubleshoot.  I know there are multiple grounding points
on a bike, but they are limited in number, location, and number of
connectors.  The locations are carefully chosen.  I do not understand
the criteria for selecting them.  

Also, if you were to ground the injector near the injector, you would
have an exposed wire that could be easily broken - washing the bike
could compromise the connection.  It would also be aesthetically
unappealing.  You argument is that is it in plain view, but you can
not tell a connection is bad by looking at it.  You could take it
apart and look at it carefully and still not see it is bad. 

I think you're nuts if you rewire the ground circuit.  Lots of
engineering went into.    

You need one of them new fangled BMW motorcycles that have CAN bus.
All the pieces communicate to each other over the bike's power wiring 

http://www.bmw-motorrad.com/com/en/index.html

Under 'services', select the 'Focus on Technology' link.  
Wayne Woodruff
http://www.jtan.com/~wayne

------------------------------