Wire size... Help!

[sailor_chic]

I'm planning on wiring my 55w  driving lights soon and I am unsure on what wire size to run from the switch to the lights. I want to use the smallest possible, but also want to make sure that it's adequate. Is a 16g possible?

[maxtog]

I'm planning on wiring my 55w  driving lights soon and I am unsure on what wire size to run from the switch to the lights. I want to use the smallest possible, but also want to make sure that it's adequate. Is a 16g possible?

My wire charts show you could probably get away with even 18ga stranded at 5 to 7 feet distance.

[sailor_chic]

That is really good news! Now is this length for the positive feed only or does the ground wire need to be included?
At this point, I am unsure if the forks are grounded, so I think I need to run a ground wire as well.

[maxtog]

That is really good news! Now is this length for the positive feed only or does the ground wire need to be included?
At this point, I am unsure if the forks are grounded, so I think I need to run a ground wire as well.

Hmm those are two good questions.  The table seems to not show much difference between 6 feet and 12 feet, so it probably doesn't matter.   Have no idea if the forks are grounded, but that is easy to find out with a meter or test light

[VirginiaJim]

I wouldn't trust them as a ground even if the meter says it is. Use a separate wire for that.

[Rembrant]

I wouldn't trust them as a ground even if the meter says it is. Use a separate wire for that.

 

[sailor_chic]

I agree with not relying on the forks to be a good ground.  So my next question is,  does the ground leg count as part of the length to determine the gauge of wire?

[jirod]

I agree with not relying on the forks to be a good ground.  So my next question is,  does the ground leg count as part of the length to determine the gauge of wire?

Yes, it becomes part of the circuit when you add it. Its resistance  needs to be taken into account. The same current (amps) flowing through the + wire flows through the - wire.

[sailor_chic]

That's kinda what I thought.  Thanks for explaining it in dummy terms for me to understand.

[Deziner]

While 18 ga may be "enough", 16 ga would be more appropriate.  The larger the wire, the less voltage drop. (Within reason)  If I were doing that job, I would also use a normally open relay and use you activation switch to complete the circuit to ground for the relay.
 Having worked on high end vehicles for the last 25 years, my idea of "proper" is probably a bit different than those who subscribe to the "good enough"  way of thinking. ......

[connie_rider]

I'm not a electrical guy. I know just enough to be dangerous,,,,
BUT, you might want to consider Murph's head Light harness.

It comes with the relay Deziner mentioned, which helps take the amperage load (with voltage drop) off of your head light switch,,
     "and" it has a pin/wire that is intended for use on additional lights...

NOTE:  I think I recall that the extra pin/wire "only" has power when your on low beam.
           So, You might; want to add a switch for the driving lights,
                                  want to add a diode so that you can power the driving lights while on low and high beam...

Ride safe, Ted

[B.D.F.]

Just my opinion but really I do not think you want to use the smallest gauge wire possible: that will cause a significant voltage drop and that will result in a significant light output drop as well. But 16 ga. wire is not the minimum and should be fine for your purposes.

As to the ground method: I would not use anything for a ground that has a mechanical, moving joint such as anything mounted to the front end of the bike; doing that makes the moving joint (the bearings in the steering head) part of the conductor and that is a bad idea on several levels. I would use the same size wire for both hot and ground, and run the ground back to at least the main frame (the aluminum casting under the fuel tank) or the battery terminal.

Wiring is just one of those things that is as easy to do well as it is to do shabbily and only one of those two methods will work well, trouble- free and for a long time. Use decent wire if you can get it, good connection method(s) (soldering, or crimp connectors with GOOD connectors being correctly crimped) and add a dab of grease to the wire before crimping it into any connector (but not if soldering). That will keep the wire waterproof and prevent corrosion in the future.

Brian

I'm planning on wiring my 55w  driving lights soon and I am unsure on what wire size to run from the switch to the lights. I want to use the smallest possible, but also want to make sure that it's adequate. Is a 16g possible?

[sailor_chic]

I am planning on powering these lights off of a Fuzeblock, through a new auxiliary switch. So I don't think an additional relay isn't necessary?
Brian, please describe a "good"  connector. Perhaps a link for a place to purchase.

[Deziner]

The purpose of a relay is to make it possible to use a smaller (lower amp rating) switch. The reason is twofold,
1.  A smaller switch is easier to mount and is more ergonomically pleasing in addition to being more aesthetically pleasing.
2.  There is virtually no electrical load on the switch itself, the load is handled by the relay. If you choose to wire the lights to be on as soon as the headlights energize, there is no additional load on the ignition switch.
Bottom line: It's YOUR bike. Do as you wish. I am merely trying to provide good information, the type a professional would give.

[maxtog]

I am planning on powering these lights off of a Fuzeblock, through a new auxiliary switch. So I don't think an additional relay isn't necessary?

As others have said, the "best" way to wire something that is pulling more than several amps is through a relay to lessen the load on the ignition circuit and switch.  It is more complex, though, and has more potential failure parts.  In some cases, you have no choice- for example adding an air horn, the horn switch was never designed to carry more load than the little "beep beep" that is included.  Just depends on how much load, where the load is being placed, how far away it is, and what type of switch you want to use.

Brian, please describe a "good"  connector. Perhaps a link for a place to purchase.

The worst possible connectors are the "scotch lock" type that cut into insulation because they make poor and unreliable connections and weaken the original wire.  The next best type are the "posi-tap" type that pierce the insulation... but those are generally only good for very low wattage.  The next best type would be spade connectors that are crimped on.  And the next step up from that would be spade connectors that are soldered on.  Either of the last two should probably be of the insulated variety.  I believe your fuse-block will have spade type connectors built into it.

All additional connections to the battery MUST be fused.  But if you are using a fuse-block, you have that covered.  And a nice installation will also color code the wires, typically red for hot (+) and black for ground (-) or some other color set with the lighter color being positive and darker being negative (you can do the same for the connectors).

[sailor_chic]

Hmmm, maybe I am mistaken or just being a dingy blonde. I was under the assumption that the Fuzeblock has a relay built in already, and that is one of the advantages to buying this $90 item.

[Rembrant]

Hmmm, maybe I am mistaken or just being a dingy blonde. I was under the assumption that the Fuzeblock has a relay built in already, and that is one of the advantages to buying this $90 item.

It does have a relay built in, but it's purpose is controlling your accessories so that they power on and off with the bike. It isn't really meant to be used as a single relay, although I suppose you could if you wanted to. Only problem is, if you do that, you would lose the ability to have any other accessories power on and off with the bike.

The Fuzeblock has a 12vdc pos bus, and a 12vdc neg bus, with 6 terminals each. Of the six positive terminals, they can all be set individually to be constant power, or switched accessory power....it depends on where you put each fuse. So, you could technically use the built-in relay for a single use, but you would lose the potential of having 5 other switched pos circuits.

The built-in relay is a selling feature when compared to the traditional aux power supply blocks that just gave you extra terminals to connect stuff to but were powered at all times.

I've been using FZ-1 Fuzeblocks for a long time...I quite like them. Twisted Throttle sold their own branded Fuzeblock for a while, but I believe they are selling a different model now.

Rem

[Rembrant]

Oh...another thought, if you wanted the lights to be on at all times, then yes, I suppose you could power them through the relay in the on the switched side of the Fuzeblock.

[B.D.F.]

Excellent- we always like professional information. So are you suggesting all electrical devices should use a relay to switch them on and off? And if not all things require a relay, what would be the point at which something did require a relay..... professionally speaking of course.

 

The purpose of a relay is to have the ability to switch large amounts of current while providing a shorter electrical path, less overall circuit resistance (to the load, who cares about the switch) and the ability to switch said load ON / OFF from a more remote location. Five amps is not a large electrical load, and there is no advantage in this case to use heavier gauge, shorter wire between power source and load (the lights) and a lighter, longer set of wires to the switch; that would merely serve to complicate the job at hand, cost more in materials and provide no advantage whatsoever.

But of course, everyone should do as he / she pleases.

Brian

The purpose of a relay is to make it possible to use a smaller (lower amp rating) switch. The reason is twofold,
1.  A smaller switch is easier to mount and is more ergonomically pleasing in addition to being more aesthetically pleasing.
2.  There is virtually no electrical load on the switch itself, the load is handled by the relay. If you choose to wire the lights to be on as soon as the headlights energize, there is no additional load on the ignition switch.
Bottom line: It's YOUR bike. Do as you wish. I am merely trying to provide good information, the type a professional would give.

[B.D.F.]

Good crimp connectors are solid copper, have brazed joints, internal (Easy Boys! not you Nicole    ) grooves to grip, have thick walls and are tin plated to resist corrosion.

Lousy crimp connectors are very thin, often brass (cheaper than copper but neither as good a conductor and not as ductile so it does not crimp as well) and tin plated to disguise the poor material used. :-)

A couple of good brands are T&B and Panduit; I personally use Panduit and find them excellent. This is an example: http://www.digikey.com/product-detail/en/BS14-M/298-9983-ND/447757  These are not protected (so they can be crimped properly and the crimp verified) and require something like shrink- tubing to insulate them.

The crimping tool is also very important: This is an inexpensive, poor combination crimping / stripping / use bad words tool: http://www.advrider.com/forums/showthread.php?t=847176    This is an excellent, ratcheting crimping tool: http://www.kctoolco.com/wiha-crimper-for-non-insulated-terminals-p/43632.htm    Of course, the second tool is a big ridiculous in cost for the casual user. But there are inexpensive tools that will yield an excellent crimp, such as this one: http://www.amazon.com/Pc-Accessories-Terminal-Crimping-Installation/dp/B00EE4JW7K   

The other option is soldering which is also very do-able for the casual, home user. It requires a bit of skill but not a whole lot and there are a LOT of tutorials on the 'Net as to how to solder. A cheap soldering gun will suffice for any / all soldering jobs on a motorcycle. Again, some type of insulation is needed to cover the bare wires and again, shrink tubing is excellent. Electrical tape is adequate but tends to unravel, leave sticky residue all over the place and is difficult to use neatly (read: us mere mortals cannot make electrical tape covered junctions look decent).

And remember, good soldering, like good sex, is 'hot, wet and shiny'. Bad soldering.... well it is cold, dry and dull. :-)

Brian

I am planning on powering these lights off of a Fuzeblock, through a new auxiliary switch. So I don't think an additional relay isn't necessary?
Brian, please describe a "good"  connector. Perhaps a link for a place to purchase.