Trouble adding Piezo bridge+preamp

[Brutha Tool]

Morning y'all. So I'm building a custom semi-hollow body for a friend and while I've got the HBs figured out including coil splits, series, parallel etc. The problem I'm having is adding the piezo bridge+preamp. With it wired into the system I get a squeal/tone that gets louder as the preamp volume is turned up. Would this be because I also ran an independent ground to the bridge? This thing is driving me crazy!! Thank you in advance for any and all helpful tips, tricks and suggestions.

 

[jeremy]

welcome to the forum!

which preamp did you use?

 

[Brutha Tool]

It's one from guitar fetish. And thanks for the welcome and any help you might be able to give me

 

[Mincer]

Is there a particular wiring diagram you are using?

 

[Brutha Tool]

 

[Brutha Tool]

This is the diagram for the rest of said build. Been trying to add the piezo bridge and GFS preamp to it for my friend. Tons of firsts on this one and I've been amazed I got all of the rest of it right, but the rest, the piezo etc, is the only thing left to do

 

[Brutha Tool]