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What difference does it make by either sending all electrical grounding wires to the battery negative post as oppose to grounding them to the frame?
 

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Grounding copper wires through aluminum can cause a galvanic reaction that can weaken the aluminum. Usually not a good idea for stress members such as a motorcycle frame.
 

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Grounding copper wires through aluminum can cause a galvanic reaction that can weaken the aluminum. Usually not a good idea for stress members such as a motorcycle frame.
I've heard this stated before, and it always brings up two questions in my mind:

a) Has anyone ever had a frame member failure where this was proven to be the cause?

b) A lot of main electrical cables, especially main feeder lines in homes are aluminum wire. Why isn't this considered a problem there, since they attach to copper members, such as the terminals in breaker boxes?
 

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What difference does it make by either sending all electrical grounding wires to the battery negative post as oppose to grounding them to the frame?
As a trained electronic tech, frame grounding is one of those things that has always weirded me out about automotive wiring. I mean, if it's supposed to be a door panel, floor pan, front bumper or whatever, why would you want to have all those points tied to one of the battery terminals? Is it supposed to save money on wiring or what? Practically speaking, on cars I've owned, a lot of fuses got blown when wires came adrift and grounded themselves by mistake.

The galvanic action argument between copper and aluminum has some merit. Automobile connections used to fail when body panels rotted out.

I think the real reason for running separate power and ground leads has to do with correcting a system that was just plain wrong in the first place, however, since computers are now part of these bikes, having the ability to precisely control where signals and power flow is a very good idea.

This is speculation, mind you, but as a life-long tech, it just made fundamental sense to me when I discovered the Vstrom was wired the way it is.
 

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^^^^^^^^^^

Since most of my farkles are on the front of the bike, I just run a 10 gauge wire from the battery neg to the front of the bike somewhere, then attach a half-dozen or so short pieces of thinner wire, like 14 gauge to that wire. Crimp on (and solder if you're anal) a male bullet connector to each short piece of wire, weather-proof the connections, and you've got a grounding buss (I call it a grounding spider) ready to go for whenever you need a new ground.

When you add a new farkle just cut the supplied ground wire to length, slap on a female bullet connector, and plug it in. Cheap and relatively foolproof. Also, if one of your farkles starts acting up you know where the ground is. :D
 

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When I used to sell Audi's much was made of the possible reaction when connecting Aluminum body panels to steel parts; in particular in the presence of water and salt. I don't think the aluminum part will fail so much as the connection can be very susceptible to corrosion which can then in the long run cause failures.

I sell Porsche's now, which use a lot of Aluminum, and I don't seem to hear as much about these issues.

As far as aluminum wiring, was there not a lot of concerns with potential fires as a result of the same corrosion when connecting to non-aluminum metals?

..Tom


a) Has anyone ever had a frame member failure where this was proven to be the cause?
...
 

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As far as aluminum wiring, was there not a lot of concerns with potential fires as a result of the same corrosion when connecting to non-aluminum metals?
Fixtures that take either Al or Cu wiring have been in use for decades. In the old days they used to sell a paste called Noalox for terminals that weren't the Al/Cu type.
 

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Put the grounds in a crimp on eye and be done with it. They're steel, and cheap. No worries about possible galvanic corrosion on your frame...which would take a very long time before it affected any structural integrity.
 

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Grounding to the frame

For Audio Equipment grounding to the frame is a bad idea, spurrious ignition noises, alternator whine etc can be picked up by the big antenna (frame) you also never know where the problem is when checking out a problem. If you ground back to the battery you always know where to look. When I wire a bike for audio equipment I keep the circuits seperate, route one power cable and ground to the front of the bike, attach this to a terminal block with 4 + 4- terminals, then secure all wiring to accessories via the terminal block and crimped and soldered lug type terminals. things do not come loose and if one has a problem you know where to look for the problem. If I do have ignition noise in the system I first try to isolate it by disconnecting one audio device at a time. If this does not eliminate the problem I will change the type of wire from 12 gauge unshielded to coax cable using the interior copper wire only for + and a seperate coax cable for the _. If this does not quiet things down I then add a noise filter.
 

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What difference does it make by either sending all electrical grounding wires to the battery negative post as oppose to grounding them to the frame?
Would you take the word of the Suzuki engineers who designed your bike? They're pretty adamant about not grounding to the frame or subframe components. It was in the owner's manual; it doesn't seem like they'd bother mentioning it there if they didn't have a good reason.

Why risk it when it's so easy to pull a wire?
 

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For Audio Equipment grounding to the frame is a bad idea, spurrious ignition noises, alternator whine etc can be picked up by the big antenna (frame) you also never know where the problem is when checking out a problem. If you ground back to the battery you always know where to look. When I wire a bike for audio equipment I keep the circuits seperate, route one power cable and ground to the front of the bike, attach this to a terminal block with 4 + 4- terminals, then secure all wiring to accessories via the terminal block and crimped and soldered lug type terminals. things do not come loose and if one has a problem you know where to look for the problem. If I do have ignition noise in the system I first try to isolate it by disconnecting one audio device at a time. If this does not eliminate the problem I will change the type of wire from 12 gauge unshielded to coax cable using the interior copper wire only for + and a seperate coax cable for the _. If this does not quiet things down I then add a noise filter.
In the case of wiring for audio equipment, use shielded cable. Two wire Belden cable with a shield wire will do you fine. You connect one end of the shield wire to chassis ground and it should eliminate any RF issues. I built 200KW generators for the film industry where you're running 24V systems beside 600V systems so RF is a big issue. Your alternator is basically a big RF generator, so you need to shield against it's ability to create sympathetic voltage in your wiring. If all else fails and you're still getting spurious signals, drop a diode in your ground wire back to your audio unit. It acts like an electrical check valve allowing the power to only go towards ground.
 

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Washers

Grounding copper wires through aluminum can cause a galvanic reaction that can weaken the aluminum. Usually not a good idea for stress members such as a motorcycle frame.
Back when I was working on aluminum framed aircraft as an electrician, we grounded almost everything to the frame. We got around the dissimilar metals equation by using aluminum washers against the frame and anodized alloy grounding studs. The only problems I ever saw was on 50+ year old airframes that I was re-wiring. Even then, all I had to do was burnish the area, put on a new washer, and go on to the next one.

All that being said, I'd still use the grounding buss as described above. :mod2_stupid: There's a big difference between 25,000 miles of wire on a 200 foot long aircraft and a couple feet of wire on a 7 foot bike. The added weight on the bike will be negligible.

My $.02.
 
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