I posted this in the other GT forum:
When I cranked it up this afternoon, I checked against the office building windows and the low beam was on. good sign, as to me, that means the bike was over 12.5 volts...maybe. I assume that is how the initial "light coming on after start" feature works! I checked when I got home and the light got brighter as I revved the motor. Another "phew!"
I put it on the charger and it was charged in a very short while. Voltage at rest was 13.2. On but not started = 12.8 ish (I didn't write anything down) and after start (about a 1.5 drop) it was rock steady at 14.1! The message remains, but at least I know the bike is charging/running right. It must be a sense wire of some sort! This should be fun!
Originally Posted by voxmagna
I don't have a GT wiring diagram, but the battery/ignition light warning is usually driven directly from one phase of the alternator, before the regulator, but with a simple electronic voltage inverter. Sometimes this inverter is part of the alternator regulator unit, sometimes it's a separate small box in the instrument cluster. So when the alternator is stationary the light is on, and when it rotates the alternator voltage turns it off.
If this is the case, then either the circuit driving the warning is faulty, or the alternator is producing no output. You have to find out if your alternator is able to match the load. You probably know how to do this - With the bike left a few minutes the battery voltage should settle to about 12 volts, after starting and running you should see about 14.5 volts and the same with all the lights/grips on at about 4Krpm.
The order of possible failures to look at (generic, not GT specific!) is usually the following with associated wiring:
Any fuses in the alternator control circuit.
CANBUS...This is what kept me away from these new bikes for some time! No fuses!!! The above addresses this one.
Any electronic 'inversion unit' if not integral with alternator controller (check input voltage present when alternator is running)
The "exciter" voltage I am assuming is good, as the alternator is putting out.
The alternator control regulator itself.
Seems fine as the voltage was rock solid while loads (small) were applied. When I have time, I'll load it up heavily and see what happens.
The rectifier diode stack (may be integral)
I'm sure it is integral, and this may still be a problem. This will be hard to isloate!
it is too new for this one! I'll know more when I load it up and see how it does. (short of tearing it apart, which with a new bike and warranty I doubt I'll
Alternator is actually rotating.
I don't know if the GT has something else electronically clever, but usually battery charge warning is deliberately kept very simple.
I think it has many very clever little things to it!!! This was my only real issue with buying one of these new bikes. If an aircraft manufacturer (Airbus) can't really get these kinds of things working, I have my doubts how perfect a motorcycle manufacturer can get it early in the game!
Hope this helps - VOX
It certainly does, and I very much appreciate your help! It is nice to see a great mechanically minded (and obviously experienced) fella is out there offering up help! Your suggestions were right on and I'll let you know what I find, when I get time to play with it. I think the idea of one phase being bad might be the direction I will follow. I need to see what the manual says about what exactly drives the warning circuit.
For now, I'm confident the battery is charging, so I'll treat it as an indication problem instead of worrying the bike will die at any minute or not start when it is parked. Keep your fingers crossed that I'm right so far!!!