Z series deck now makes loud clicking thru all speakers

[lilbum]

Hello

 

I have a Z-1( made into a Z-3) which now makes a loud static clicking noise thru all the speakers with car running or just in the on position ( deck still works though). It was making a loud popping noise thru the front left speaker but now it just clicks as well. We tried different amps same result, tried regrounding it, ground loop isolators, noise suppressors, no luck. It goes away when I disconnect the RCA'S from the amps. I read that some Pionner decks have an internal fuse linked to the ground which pops very easy.When it goes the deck searches for a ground else where , ie the RCA'S, so I grounded a wire and touched the RCA'S when plugged into the amp and the noise gets much quiter. A local repair tech said that's not possible , but I'm out of ideas. Does any body have any thoughts?

I also called Pioneer car audio tech support , they're seemed to know nothing at all about their own products.

 

Thank you