Several months ago, I saw a comment from someone who had done a fan threshold modification to their 590SG, that lowed the temperature at which the fan turned on. If I remember correctly, the modification involved a resistor either across or in series with the existing sensor. I run a lot of high-duty cycle modes, and I am curious about what is involved in such a mod. I have been searching the web for such a modification, but I haven't found anything close. Have any of you done this, or do you know where it has been written up?