Fender Custom Jazz five string treble hum

[gpandolfo]

I recently purchased a Fender Custom Shop 5 string with "noisless" pick ups. Great instrument except I get an annoying high-end whistle from the treble tone control. When the control is turned off it is perfect but no high end; as soon as I turn it up at all I get the whistle. Help?

[jjk2007]

Maybe try a fresh 9 volt?

[gpandolfo]

I replaced the two 9 volts; no change
tried changing amp ground lift and it affects both pick ups