I got a GSX-R 750 and would like to connect my usb charger. On my previous bike I ran it straight to the battery, but I want to do a proper job this time. Don’t want to connect to the ignition circuit as if something goes tits up and blows a fuse last thing I need is a bike that cannot start.
Any suggestions on the best place for this so that I will only have power when the ignition is on?
It is usual to wire it into a switched connection.
My GPS is wired into my Tiger’s rear light.
It is a good idea to put a fuse between the usb charger and whatever you are wiring it into.
Generally, you’ll:
Get a 12V relay from somewhere like halfords. It’ll have four pins, numbered 30, 85, 86 and 87. You might get a fuse holder, too.
Find a switched live. That is a wire that becomes live when the ignition is turned on, and stops when it’s turned off. The power for the headlights or fuel pump are popular for this.
Take a line off that switched live (scotchblocks are popular if also popularly inadvisable) and connect it to pin #86
Connect a wire between pin #85 and the battery’s negative terminal (perhaps via something else connected to it, like a chassis)
Connect a wire between pin #30 and the battery’s positive terminal. Ideally you’ll put a fuse here, having considered the right rating
Connect the live line for your USB charger to pin #87
Connect the negative line for your USB charger to the negative terminal of the battery (or the chassis).
That done, whenever your switched live comes on (which would normally be with the ignition) it’ll close the relay and your USB charger will get power. When your switched live switches off, the relay will open and turn off your USB charger.
thanks guys will give that a go, thats my weekend project sorted. what amp rating should the relay be? maplin shows a 40A and a 30A.
Either of those will be fine, you’ll be drawing something of the order of 3A.
whats the problem with scotch blocks they will give a neater job than electrical tape???
I find them fine, but The Internet seems to often have issues where they slowly separate, and then much as your additional thing might work, the wire you spliced into doesn’t any more.
in theory they’e ok but soldering a wire in properly is the best way of doing it.
The problem with soldering it is that you make a rigid portion of the wire so it’s more prone to cracking, especially since the junction’s almost certainly not somewhere there’s supposed to be one. The best way is to properly teminate it with a connector that allows for the extra line but nobody’s really up for that faff.
I do agree that ideally you want to terminate with a new connector, but I just hate the idea of such a permanent fix/change. when I remove the fairings I will see what is the best option.
