If the generator light is on all the time...... well, it should not be.
This makes me think you have a grounded generator light circuit.
if this circuit gets grounded, the generator will simply dump all of it's output into the ground. The result will be a discharged battery.

To check this, do the following. I have marked what I suggest you do:



pg

 

where does the ground line of the gen light go then because my wireing diagram in my HD manual says it goes to ground....

 

The generator light up through 1976 has two wires. One is attached to the 'GEN' terminal on the voltage regulator and the other wire (indirectly) connects to the 'I' terminal of the ignition switch.
With this set up, if there is a ground somewhere either in the wiring or a short at the base of the bulb, the light will stay on. This dumps the generator charge to ground.

Your machine is a 1981. If your manual shows the signal light with a wire going to ground, then that is different from what I am accustomed to seeing.
So, what does your manual tell you to do with regards to 'Checking the Generator Signal Light?'
pg

 

There should be diode between regulator and generator light, in all systems that have electronic regulator. -77 new bikes came with electronic regulators. Check that diode is ok. It can work without that but...

 

so after a few weeks of not having time to work on the bike problem i totally disconnected the gen light from the system. now for some odd reason the gen is only producing 6v when the bike is running. im so frustrated with this I dont know what to do anymore.