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Fuse Block Installation

8/15/2010

There are two popular ways of wiring up accessories to your bike and variations of each of them depending on who you talk to. Wire TerminalsThe first, and simplest way, is to wire your accessory directly to the batteries positive ( + ) and negative ( - ) terminals. This is easily accomplished by adding a spade or ring terminal, like the ones shown in the picture, to the end of the wire you will be connecting to the battery.

This method is the most straightforward method if you are only going to wire up one accessory like a GPS or a power cord for a heated jacket liner. However, if you are going to be wiring multiple accessories to your bike this method can quickly have you dealing with something that resembles a bowl of spaghetti on your battery terminals.

The second method, and the one I prefer, is to wire your accessories to a fuse block (also called a distribution block). The reason I prefer this method is that, even though the plan might be to only install one accessory, wants and needs change and down the road you may want to install additional accessories. If you start off just wanting to wire up a GPS and find out later that you want a set of driving lights or a heated liner connector you have a good amount of the work done already if you installed a fuse block with your first accessory.

When wiring accessories and fuse blocks up I prefer, and recommend, running your power and ground feeds for the fuse blocks back to the battery and grounding all of your accessories back to the fuse block instead of hunting for frame locations. By doing this you greatly reduce the chances of having ground loop noise in any audio accessories you decide to power off of the bike.

As with most accessories you have different brands of fuse blocks to pick from but for the most part there are two popular styles on the market. The two styles I'll focus in on are the fuse blocks that are just made for the positive feed and the ones that have a positive bus and a negative (ground) bus built into the same fuse block.


Centech FB-4 The first style we'll look at is the basic power only block (left). Not only are they less expensive than the combination blocks but they are usually smaller which makes them ideal for installations in more confined areas. The drawback is that, you need to ground your accessories somewhere, and going back to my rule of terminating everything in one location you'll need a ground block (right) and a place to mount it. For troubleshooting reasons, the closer together you can keep the power and ground the better off you'll be. Ground Block

Fuse Block & Ground Block wiring

Wiring the power and the ground block are pretty straight forward. All you have to do it connect your power block and ground block to your battery. You want to make sure and use a wire that is thick enough to carry the current of all of the accessories you are going to add. I like to use 10gauge wire for my power and ground connection to the battery but your needs may dictate that you use a thicker gauge.

If your power block is more than a couple inches away from your battery connection I recommend an inline fuse close to the battery. This will help protect your wiring should your power wire short out for some reason.

This brings me to another point. Zip Ties are your friends. Wires that are left loose have a greater chance of wearing through the insulation and shorting out. If you secure your wires to something like a factory wiring harness or frame rail you will reduce your chances of chaffing and wearing through the insulation.

Once your fuse and ground block are wired up all you have to do is route the power and ground wire from your accessory to the appropriate block, connect them, and again secure them to reduce the chances of chaffing.


The second style of fuse block we'll look at is the style that has both the positive and the negative bus built into one unit. These units are usually larger in size than the power only blocks but can make installing accessories much easier because all power and ground wires go back to one location on the bike.

The two most popular brands you'll probably hear of are the Centech and the Blue Sea. There are slight design differences between the brands but what drives the selection process with most of the people I talk with is space. The Blue Sea 5025 (6-devices) is larger than the Centech AP-1 & AP-2 (8-devices) so in the situations where space is an issue the Centech is usually selected.

Centech AP-1 AP-2

Fuse Block & Ground Block wiring

Just like the earlier example of wiring a separate power and ground block, wiring either the Blue Sea or the Centech fuse blocks to your bike is a pretty straight forward process. Both of these units have a power and a ground lug incorporated into the design so you simply take your power and ground from the battery and connect them to the fuse block.

Once your fuse block is wired up all you have to do is route the power and ground wire from your accessory to your fuse block, connect them, and again secure them to reduce the chances of chaffing.

There you have it, we've just covered some of the most basic ways of connecting accessories to your bike, both with and without a fuse block. These are the simplest methods to wire an accessory to your bike and mean that your devices will have constant power to them, even when the bike not running. This of course increases your chances of returning to your bike to find a dead battery because you forgot to turn an accessory off.

In the next article we will use the same examples and work on incorporating a relay into the install so that the fuse block powers down whenever the bike is turned off.

Model
Dimensions
Circuits
Ground Bus
Terminal Location
Blue Sea 5025 4.9" x 3.32" x 1.52"
6
Y
Internal
Centech AP-1 3" x 2.4" x 1.25"
8
Y
Internal
Centech AP-2 3" x 2.4" x 1.25"
8
Y
Internal
Centech FB-4 3.5" x 1.75" x 1.5"
4
N
Side
Centech FB-6 4" x 1.75" x 1.5"
6
N
Side
Powerlet PMI-002 & PMI-019 2.5" x 1" x 2"
4
N
Raised Bottom
Fuzeblock FZ-1 3.25" x 2.5" x 1.25"
6
Y
Side

Various Fuse Block Spec's

If you are interested in learning more about basic troubleshooting and repair of your bikes electrical systems there is a very good book that you might want to add to your collection appropriately called Motorcycle Electrical Systems Troubleshooting and Repair .