Battery died

[Big Bird]

Hello all.
So riding my '89 FJ 1200 the other day. All is fine.  Stopped at my son's house for dinner.  Went to move the bike, Battery real weak.  Wouldn't crank.  Ran home since I live close buy and got my battery charger.  when I went to hookup the charger the tach jumped to 6k rpm.  Mind you the bike is not running and the ignition is off.  I tried again and all was fine.  Battery was stone dead.  Let it charge for an hour or so, fired it right up, took a longer route home to see If I could duplicate the issue.  Got home shut the bike off went to start it back up and it fired right off, but I did notice that my headlight and front signals would flicker at a regular interval.  Now the headlight gets brighter when you rev it up and the flicker interval gets shorter.  Weird.  Any thoughts?

[jscgdunn]

Check battery connections for tightness/corrosion.  How old is battery?

[Pat Conlon]

Hey BB, here's a quick half dozen points you should follow in order:
1) How old is the battery?  What's the resting voltage?
Weird shit happens to our FJ's with a dodgy battery. Really goofy stuff.
2) Are your connections tight? The flicker indicates a loose connection.
3) Check (unplug and examine) the condition of the red plug under right side panel. It melts.
4) Is your charging system working? You should be reading 14-15 volts at the battery @ 3k rpm.
5) Do you have a parasitic drain on your electrical system? Put a multi tester in line and check it out.
6)  Check the wires going down to your horn. They are hot and the handle bar horn button grounds the circuit.
With the side to side motion of the front forks, it's common to have those horn wires chafe against the steering neck.

It's common to have the headlight dim and brighten as the engine increases the charging voltage.

Electrical diagnostics 101: Start with a fresh battery.

[balky1]

Hey BB, here's a quick half dozen points you should follow in order:
1) How old is the battery?  What's the resting voltage?
Weird shit happens to our FJ's with a dodgy battery. Really goofy stuff.
2) Are your connections tight? The flicker indicates a loose connection.
3) Check (unplug and examine) the condition of the red plug under right side panel. It melts.
4) Is your charging system working? You should be reading 14-15 volts at the battery @ 3k rpm.
5) Do you have a parasitic drain on your electrical system? Put a multi tester in line and check it out.
6)  Check the wires going down to your horn. They are hot and the handle bar horn button grounds the circuit.
With the side to side motion of the front forks, it's common to have those horn wires chafe against the steering neck.

It's common to have the headlight dim and brighten as the engine increases the charging voltage.

Electrical diagnostics 101: Start with a fresh battery.

I would just add to this that you should check the elctrolyte level if you have wet battery and do this often, especially with high ambient temperatures.

[Big Bird]

Thanks for the tips guys.  Battery is new, 3 moths old.  Now that you mention it the horn is hit and miss.  Will work on it this evening and let you know what i come up with.  What really sucks with all this is that I just signed up for a track day at Road Atlanta in August. It is also a Yamaha Demo ride event.  Really want to get the FJ out there and really be able to open it up.