Installing an aux fuse box on a R1200RT with relay

[Deek]

I installed an BLue Sea 5025 auxiliary fuse box under the seat in my R1200RT yesterday. I did that mainly because I plan to add Hyperlight tail/brake lights soon, and I need a source for switched 12vdc power. Figured I might as well connect a relay to that switched source and add the fuse box now. For now just my Gebring heated gear controller is connected to the aux fuse box.

 

For those of you who might not know about it, the Can-Bus makes installation of electrical accessories a little more complicated than on non Can-Bus motorcycles. Usually the difficulty can be solved by installation of a fuse box that is connected directly to the battery, or indirectly to the battery using a switched power source. There are other switched power sources available, but I like to use the one in the photo below. The wire I use is the YELLOW/BLACK wire in the photo below (you can only see YELLOW due to the angle of my picture). A relay, of course, takes the little bit of current in that wire, and acts as a switch to turn on the relay which then powers the fuse box whenever the key is turned on.

 

One thing that is confusing regarding relays is the instructions you find on the internet are NOT standard, and that can be confusing. below is what I think is correct, or at least I know it works on my motorcycle.

 

The relays I use have 4 contacts numbered as below:

30

87

86

85

 

I connect them like this:

30 is connected to the motorcycle battery's PLUS terminal via a 30amp fuse.

87 is connected to the accessory needing the battery's PLUS side, in my case a fuse panel.

86 is connected to the source of switched 12vdc power, in this case the YELLOW/BLACK wire in the photo.

85 is connected to the battery's GROUND terminal.

 

HOWEVER: Many places on the internet swap things around and interchange the connection location for the 30 and 87 (high amp 12vdc), and the source for 86 and 85. I suppose that would still work, but I'd always used terminal 30 to the battery's plus, 87 to the accessory, 86 to the switched power source, and 85 to the battery's negative side.

 

IF ANY EXPERT NEEDS TO CORRECT ME, PLEASE DO! I hate to get incorrect info on the internet and it does happen.......

 

 

 

 

 

[Ken H.]

The polarity of 30 and 87, or 85 and 86 makes no difference. It's just a DC coil and contacts acting as a switch.

 

But for the record, I usually do it exactly as you listed, but that's mostly because it's what I keep it in my head.

[TestPilot]

The 85-86 polarity WILL make a difference if the relay uses a diode across the coil for transient suppression or if you decide to add one yourself.

[dirtrider]

Hi Karl

 

Only makes a difference for a nano second then it reverts to standard non suppressed relay. I do agree they should be hooked up correct polarity if nothing more than for future trouble shooting by someone other that the person that installed it.

 

[TestPilot]

If the diode is forward-biased instead of reverse-biased, it may essentially short out the relay coil and the relay won't function/

[dirtrider]

Hi again Karl

 

Those diodes aren’t that robust, they just pop when the a full current load is run through them. They will take a test light load but not much more than that probably no more than .25 to .5 amps.

 

[Deek]

Hi again Karl

 

Those diodes aren’t that robust, they just pop when the a full current load is run through them. They will take a test light load but not much more than that probably no more than .25 to .5 amps.

 

For those of us who are almost completely ignorant, are my relay connections "proper" to avoid any of what you guys are discussing with such technological savvy? It will probably be another 3 yrs before I install another relay, but I want to be sure I've done it the "standard" or "proper" way for all contingencies.

 

Thanks!

[Ken H.]

Yes.