Re: 2004 R1100S Fuses

[plpklt@xxxxxxx]

- -----Original Message-----
From: Steve Makohin <wateredg@xxxxxxxxxxxx>
To: oilheads@xxxxxxxxx
Sent: Mon, 28 Nov 2005 00:44:01 -0500
Subject: Re: 2004 R1100S Fuses


Hello Paige, 
 
- ----- Original Message ----- From: <plpklt@xxxxxxx> 
 
> -----Original Message----- 
> From: Steve Makohin <wateredg@xxxxxxxxxxxx> 
> To: oilheads@xxxxxxxxx 
> Sent: Sun, 27 Nov 2005 19:02:56 -0500 
> Subject: Re: 2004 R1100S Fuses 
> 
> Hello Paige , 
> 
> From: <plpklt@xxxxxxx> 
> 
>> I think the R11s must have the worst electrical system 
>> ever put on a beemer. My son melted the entire back 
>> section of wiring down, That was fun sorting that mess 
>> out. They use the smallest gauge wiring and it seems to 
>> melt right down to the connectors so it is hard to splice 
>> in a new section of wire. 
> 
> I don't understand the nature of your problem. I've had two R1100Ses, and > put tens of thousands of miles on them, all without a hint of any sort of > issue, including electrical. I wired in a GPS, intercom, and accessory > plug (twice, once on each bike), all without any hint of issues. 
> 
> Steve, 
> note none of you accessories was added to the rear harness, I think that > is where the weakness in the wiring is. 
 
Actually, I ran my intercom (switched) off a point in the rear harness on my first R1100S. Yeah, not a smart move, I know, but it was issue-free, none the less. 
 
To be more candid, the position I take with respect to BMW's wiring being problematic is "prove that the issue you experienced was *BMW's* fault." I believe that virtually anyone can have problems with virtually anything, but correctly identifying fault and assigning blame is a different matter*. 
 
- -Steve 
 
 
Steve,
 
I understand what you are saying and greatly respect your point.  I too like to fully examine and explore issues in hopefully an open minded way.  I also love a good debate and a good debater.
 
My point is that on the R11S, what I found was very light gauge wiring with thin insulation.  I think that on the r11S they were trying to save weight in anyway they could.  I think they just lightened the wiring up too much.  Bmw doesn't use very heavy wiring anyway (based on my 96RT)  but I understand that short runs of wire don't need to be heavy when the proper loads are considered.   
 
One can well make the argument that If my son had  not tried to add anything, the bike probably would have been fine, but what he added was LED's which it is hard to imagine they  would overload the circuit, especially since most of the lights were brake lights which would have only been on a few seconds at a time, as opposed to a constant load.  Led's loads are measured in Milli-amps.
 
I also don't know exactly what he did and how, but I know he would have followed any directions that came with the hyper lights which are ususally pretty straight forward ( he reads the directions, I never do until the fire starts)....  
 
One other thing is that the bike only has 4 fuses ( If I remember correctly)  which tells me that they are not protectecting each circuit with a fuse, as you would do in a building.   When you try to protect multimple circuits with a single fuse, how do you size the fuse correctly? Ideally a fuse should be designed to blow at 80% of the capacity of the smallest wire.  If two wires melt together the capactiy of the wire is greatly increased, hence melt down.  The old slash 5 only had two fuses, but it had wiring the size of house wiring.  One fuse was used for the ignition , the other for the lighting, If you lost the lighting fuse you could atleast ride it home (perhaps in the dark). 
 
I therefore would contend..... the bike is not properly fused, probably the root problem.  The wiring is sized only for the orignal design loads, which is technically correct but we all know there isn't a beemer around that doesn't have a little doo-dad added, usually there is a little safety factor built into any design to allow a little cushion.
 
It is up to the designer to make these decisions, but a wise designer makes allowances for "field" conditons, these occurences that are likely to happen.
 
They also bundle the wires tightly with that cloth electrical tape.  This doesn't allow the wiring to disipate any excess heat.   
 
Is it a design fault? or just circumstances?  If you can anticipate a problem and do nothing to avoid it I conclude it is a desgin flaw, even if it is a passive fault.   That is how they treat it in my profession ( architect).
 
 
So what about it? did I make a case for  my rash statement?
 
Paige

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