I've been putting this off for too long but I thought I would start making some notes and posting my toughts on this subject. There's a lot of different options here and I want to stick to some of the most common ways. Then there's the different devices people want to hook up and how they want to hook it up. Some people want simple, some people want elegant, and some people want both. So this can be such a diverse topic that it's hard to include everything. This has come up so much though over the past month that I've decided I need to put some general stuff together to help people that want to get started.
Now DC voltage just isn't that tough. You have a positive voltage (12V typically) and you need a ground (anywhere on the frame will do or a ground wire somewhere on the wiring). When wiring plugs make sure that you have the postive terminal protector so when you disconnect it, it doesn't accidentally short against the frame and cause a short. A short is bad and a fuse helps protect that. Have the fuse as close to the power source (i.e the battery) makes sure that if you do have a short it will blow the fuse before it gets to the battery. If there's a short to ground on the positive terminal of the battery you're going to have a lot of sparks and a dead battery. A fuse blows when there's too much current run through it. That happens when you want to hook up a compressor to the accessory plug where the accessory plug has a 2 amp fuse but the compressor wants somewhere around 8 amps when it's working. You want a fuse to blow to protect a device and the battery.
Typically with a device you'll see the voltage it operates at and then they will give you the amount of power (watts) it consumes or the amount of current (amps) it draws. You might want to know the watts so you don't exceed the charging capability of the alternator on the bike or you may want to know the max current draw of a device if you are wiring your own harness and need to put a fuse in the line. The formula for figuring these things out is simple and is called Ohms Law. Here's a link to Ohm's law:
Ohm's Law
Now there's a lot of formulas there and they represent volts with an E (for Energy I guess) but the formulas still hold. Typically we are operating with 12V but remember typically the voltage from the bike will be closer to 13 V. Voltage times Current (Amps) is Power (Watts) or E*I=P. Then there's P/E=I and P/I=E. You can use these to figure out the amount of current a device will draw and how much power it consumes when you know the voltage (12V-13V) and one of the other components (amps or watts).
There's other things to worry about like noise, grounding loops, shorts, opens, chaffing, etc. that need to be considered also but those are all things you have to learn as you go. All of this is some background but what you really want is a way to wire up your device to the bike.
First you need to consider how do you want to hook this up to the bike. Do you want to plug the power cord into a standard cigarette lighter plug or a powerlet (BMW) style plug. Or maybe you want to hard wire the cord into the bike somewhere.
The next consideration is usually whether you want the device to be on even when the bike is off or only on when the bike is on. This is usually refered to as constant or switched. Then there's the special exceptions where you may want it on in the accessory position also.
These first two considerations should take another into account and that is how many other devices do you plan on hooking up to the bike and what kind of power and hook ups are they going to require. Also how many will be in the front of the bike versus the back of the bike. Since running power wires from the front to the back or vice versa are a challenge to get right on the ST you may want to consider a power source located close to the device(s) you're hooking up.
Once you've taken these three things into consideration you're ready to start looking for resources to help you wire up your device. Now if you have the Honda accessory plug in the right fairing pocket and you have a device that plugs into a cigarette lighter then you're pretty much set and you probably never bothered looking at this primer. There's plug adaptors to go to the BMW/powerlet style plug if that's what you need also. So all you really need is a cable for your device and the plug you need to plug into the accessory plug. Wire the two plugs together and you're set.
There's a few places to mount plugs and they have all been covered in this forum on more than one occasion. There's the Honda accessory plug inthe right fairing pocket but you could mount one in the right pocket and also you could mount a BMW/powerlet style plug in either pocket also. Another place is to mount a BMW style plug on the fairing just below the right fairing pocket. There's even been a case where NormanPCN mounted one in the middle of the handlebars using the Honda plastic cover there. There is also a powerlet plate setup that will give you two powerlet plugs down by the rear shock adjustment knob.
If you don't have the Honda accessory plug you can have your dealer install it or install it yourself. It's not difficult but drilling a large hole in the fairing right pocket may be the piece that's hard to do. To install the accessory plug you will also need to install the quartet harness. What's that? The quartet harness is a wiring harness that plugs into a 9-pin mating connector on the left side of the bike and then fans out to 4 connectors. Some of those 4 are used for the accessory plug, the heated grips, and the radio (available only in the UK). There is an article on installing the quartet harness in the articles forum here and another article that has the full pinout on the quartet harness and all of it's plugs.
Now if you're still here you probably want to hardwire a device into your bike. Well know you have to think about the third consideration I mentioned before. If you are only going to wire this device and nothing else then you can worry about wiring your device straight to the nearest 12V source (swithced or constant) and be done with it. However if you plan on possibly wiring something else in the future you may want to consider a fuseblock setup. Now usually if you can find a 12V source to plug into for one device you can use that spot to wire a fuseblock to and then put your one deivce on it and any others you add in the future. Again a fuseblock setup is optional if you just want to wire one device. There's another consideration here but it's less of an option and that is where you are going to install and use the device.
Positioning the device is usually predetermined by the device itself. If it's a something you need to access while riding it will probably be mounted in front of you on the handlebars or on the fairing (or a dash shelf). If it's lighting it may be out in front of the fairing. If it's heated clothing or brake lighting then it may be down by the seat, the frame, or back by the luggage rack somewhere. The reason for looking at this is that you need to pull power from somewhere and this can depend on where you are positioning the device on the bike. Obviously you can run wires anywhere you want but remember the longer the run the more issues you can have with pinch points and rubbing with can cause a wire to short or be cut/pinched by somehting.
There are basically 3 places that people get power from for wiring there farkles. One is from the battery itself. This is convienant for things that are mounted from the tank back. This is good for 12V constant but if you want swithced 12V then you have to use a relay and make it yourself (more on this later). For the front and handlebars of the bike it's typically the quartet harness. The quartet harness provides switched and constant 12V. There are articles that cover the installation and pinout of the quartet harness in the articles section of this forum. The third place is off the fuseblock on the left side of the bike by using a fuse-tap device. This provides switched 12V. You will have to modify the rubber cap for the fuseblock though if you want to use this which is the reason I don't like it but it easy to do and convienant if you want swithced power with less hassle. Here's a link to Add-A-Circuit Mini.
If you're hooking up one device you just have to get your positive wire of your device to one of these places and get the ground wire to the nearest ground from that (even though any frame ground will do). Now if you're going to hook up more than one device then you want to consider a fuse block. There are some good fuse block choices out there and even a couple that you can do yourself. There's the universal one from www.electricalconnection.com. There's the 12 circuit BlueSea one. The AP-1 from Centech one is also very popular. If you don't like any of those then you can build your own using one from Buss that can be bought at most automotive parts stores. The one with the ground bus is preferred but you can do your own too.
Ok more to come. I'm tired.
Now DC voltage just isn't that tough. You have a positive voltage (12V typically) and you need a ground (anywhere on the frame will do or a ground wire somewhere on the wiring). When wiring plugs make sure that you have the postive terminal protector so when you disconnect it, it doesn't accidentally short against the frame and cause a short. A short is bad and a fuse helps protect that. Have the fuse as close to the power source (i.e the battery) makes sure that if you do have a short it will blow the fuse before it gets to the battery. If there's a short to ground on the positive terminal of the battery you're going to have a lot of sparks and a dead battery. A fuse blows when there's too much current run through it. That happens when you want to hook up a compressor to the accessory plug where the accessory plug has a 2 amp fuse but the compressor wants somewhere around 8 amps when it's working. You want a fuse to blow to protect a device and the battery.
Typically with a device you'll see the voltage it operates at and then they will give you the amount of power (watts) it consumes or the amount of current (amps) it draws. You might want to know the watts so you don't exceed the charging capability of the alternator on the bike or you may want to know the max current draw of a device if you are wiring your own harness and need to put a fuse in the line. The formula for figuring these things out is simple and is called Ohms Law. Here's a link to Ohm's law:
Ohm's Law
Now there's a lot of formulas there and they represent volts with an E (for Energy I guess) but the formulas still hold. Typically we are operating with 12V but remember typically the voltage from the bike will be closer to 13 V. Voltage times Current (Amps) is Power (Watts) or E*I=P. Then there's P/E=I and P/I=E. You can use these to figure out the amount of current a device will draw and how much power it consumes when you know the voltage (12V-13V) and one of the other components (amps or watts).
There's other things to worry about like noise, grounding loops, shorts, opens, chaffing, etc. that need to be considered also but those are all things you have to learn as you go. All of this is some background but what you really want is a way to wire up your device to the bike.
First you need to consider how do you want to hook this up to the bike. Do you want to plug the power cord into a standard cigarette lighter plug or a powerlet (BMW) style plug. Or maybe you want to hard wire the cord into the bike somewhere.
The next consideration is usually whether you want the device to be on even when the bike is off or only on when the bike is on. This is usually refered to as constant or switched. Then there's the special exceptions where you may want it on in the accessory position also.
These first two considerations should take another into account and that is how many other devices do you plan on hooking up to the bike and what kind of power and hook ups are they going to require. Also how many will be in the front of the bike versus the back of the bike. Since running power wires from the front to the back or vice versa are a challenge to get right on the ST you may want to consider a power source located close to the device(s) you're hooking up.
Once you've taken these three things into consideration you're ready to start looking for resources to help you wire up your device. Now if you have the Honda accessory plug in the right fairing pocket and you have a device that plugs into a cigarette lighter then you're pretty much set and you probably never bothered looking at this primer. There's plug adaptors to go to the BMW/powerlet style plug if that's what you need also. So all you really need is a cable for your device and the plug you need to plug into the accessory plug. Wire the two plugs together and you're set.
There's a few places to mount plugs and they have all been covered in this forum on more than one occasion. There's the Honda accessory plug inthe right fairing pocket but you could mount one in the right pocket and also you could mount a BMW/powerlet style plug in either pocket also. Another place is to mount a BMW style plug on the fairing just below the right fairing pocket. There's even been a case where NormanPCN mounted one in the middle of the handlebars using the Honda plastic cover there. There is also a powerlet plate setup that will give you two powerlet plugs down by the rear shock adjustment knob.
If you don't have the Honda accessory plug you can have your dealer install it or install it yourself. It's not difficult but drilling a large hole in the fairing right pocket may be the piece that's hard to do. To install the accessory plug you will also need to install the quartet harness. What's that? The quartet harness is a wiring harness that plugs into a 9-pin mating connector on the left side of the bike and then fans out to 4 connectors. Some of those 4 are used for the accessory plug, the heated grips, and the radio (available only in the UK). There is an article on installing the quartet harness in the articles forum here and another article that has the full pinout on the quartet harness and all of it's plugs.
Now if you're still here you probably want to hardwire a device into your bike. Well know you have to think about the third consideration I mentioned before. If you are only going to wire this device and nothing else then you can worry about wiring your device straight to the nearest 12V source (swithced or constant) and be done with it. However if you plan on possibly wiring something else in the future you may want to consider a fuseblock setup. Now usually if you can find a 12V source to plug into for one device you can use that spot to wire a fuseblock to and then put your one deivce on it and any others you add in the future. Again a fuseblock setup is optional if you just want to wire one device. There's another consideration here but it's less of an option and that is where you are going to install and use the device.
Positioning the device is usually predetermined by the device itself. If it's a something you need to access while riding it will probably be mounted in front of you on the handlebars or on the fairing (or a dash shelf). If it's lighting it may be out in front of the fairing. If it's heated clothing or brake lighting then it may be down by the seat, the frame, or back by the luggage rack somewhere. The reason for looking at this is that you need to pull power from somewhere and this can depend on where you are positioning the device on the bike. Obviously you can run wires anywhere you want but remember the longer the run the more issues you can have with pinch points and rubbing with can cause a wire to short or be cut/pinched by somehting.
There are basically 3 places that people get power from for wiring there farkles. One is from the battery itself. This is convienant for things that are mounted from the tank back. This is good for 12V constant but if you want swithced 12V then you have to use a relay and make it yourself (more on this later). For the front and handlebars of the bike it's typically the quartet harness. The quartet harness provides switched and constant 12V. There are articles that cover the installation and pinout of the quartet harness in the articles section of this forum. The third place is off the fuseblock on the left side of the bike by using a fuse-tap device. This provides switched 12V. You will have to modify the rubber cap for the fuseblock though if you want to use this which is the reason I don't like it but it easy to do and convienant if you want swithced power with less hassle. Here's a link to Add-A-Circuit Mini.
If you're hooking up one device you just have to get your positive wire of your device to one of these places and get the ground wire to the nearest ground from that (even though any frame ground will do). Now if you're going to hook up more than one device then you want to consider a fuse block. There are some good fuse block choices out there and even a couple that you can do yourself. There's the universal one from www.electricalconnection.com. There's the 12 circuit BlueSea one. The AP-1 from Centech one is also very popular. If you don't like any of those then you can build your own using one from Buss that can be bought at most automotive parts stores. The one with the ground bus is preferred but you can do your own too.
Ok more to come. I'm tired.