Farkle Fuse Box?

[Berzins]

Hi guys.

Well we had a few weeks of nice weather and I had the new beast out, but now we have been back to snow for a week or so... <crap>.

Anyway, I've noticed from reading a lot of differnet posts that most of you seem to add a fuse box to your bike for all your farkles. Now for the most part I dont add a lot of stuff, and on all my other bikes I have wired direct to battery for ground and then taping off something on the bike for positive power.

So the question comes up, why do most of you do it? I have to imagine there is a good reason for it. There are of course a ton of follow up questions to the first, so hopefully someone can point me in the right direction.

1. Why the need to add another fuse box?

2. If adding a fuse box, where do you grab the positive connection? I assume it would be off a swiched (ACC) feed?

3. How do you know what size of fuse to use for whatever your hooking up? An example might be a Garmin 2610.

For the most part I will be adding:

1. Garmin 2610 GPS

2. Autocom Sport7 Communications System

So really not a lot of stuff. And funny enough the Autocom does not come with a fused leg, nor do the install instructions even talk about doing it. I had it on my Sabre for a year before ripping it out to move it to the ST, and it worked great.

Guess I am not sure the reason so do it (install the fuse box).

If anyone can give me any insight into this I would apprecaite it.

Dave...

[CruisingDog]

Dave, my feelings are thus:

Really it's best to have a fuse in-line with the wiring you do since it's possible that the wiring to the device you hook up could become the fuse!

For instance a 15A fuse may be way over rated for a GPS cable. As a result the cable might fry if it shorts and the fuse would be perfectly intact!

Another reason is that if you wire all devices directly and one of then goes kaputt, you loose power to all of them because you blow the main fuse!


As far as ratings are concerned, most devices tell you what they consume in watts. Just divide by 12 and look for the next amperage fuse above. Typically most electronic devices are way less than 2A so a 2A fuse would work well.

[georgeorge]

If you tap into an existing circuit to get power for a farkle then you are putting more of a load on a circuit that was designed to handle whatever it is that the factory put on that circuit. For example....if the factory puts a five amp fuse in the fuse box to handle the 1 thing such as the 4 amp power windshield (I don't know this to be true...just an example) and you tap into it to run your 2 amp heated grips.......then you just overloaded that circuit and 1 of 3 things could happen.
1) you get lucky and never have a problem (keep a look out for the mysterious grey smoke!)
2) you will overload the circuit and fry the fuse (this is the best thing that can happen)
3) if you develop a short in the grips that requires a 2 amp fuse to fry, but you're hooked up to a 5 amp fuse.....well.....have you ever seen the mysterious grey smoke? Not pretty when you burn up wires.

So, bottom line is that you should either add a secondary fuse box to handle the farkles or put an in line fuse for just 1 farkle. What you would do is connect a new lead right to the positive of the battery and run it to a set of contacts on a relay. then continue the circuit through the contacts...to the fuse box (or inline fuse) then to the farkle. The relay is acting like a switch to turn off power to the fuse box or inline fuse when it itself (relay) is not energized. You tap into any switched circuit on the bike to get power to energize the relay. The power consumption of a relay is minimal so you run almost no risk of overloading any existing circuit by tapping into it to get power for the relay.
Relays and inline fuse holders and fuseboxs are cheap insurance to doing your electrical farklein' correctly.

Brian