I just converted my tiller GTR to console. I noticed yesterday that when I trim up or down, there is some feedback over the speakers. Any clue what it could be??

What kind of feedback? Popping or whine?

It's a pop any time I mess with the trim. I am running a wetsuits stealth 6 along with 4 infinity 6.5 pushed by a kenwood amp. It never did it before the conversion.

I would think it's a voltage issue. Know how to work a dmm? Put a volt meter across the power and ground on the radio and watch what happens when you cycle the trim. My guess would be that you are sharing a wire now that you weren't before, and when you cycle the trim the voltage drops, the radio kinda shuts off and back on even though it may not look like it.

Sounds like that could be it. The trim used to be connected on the engine, now it is hooked directly to the battery. Any easy remedy?

Run heavier power wire, run a dedicated power and ground just for the stereo, do what you can to isolate anything to do with the radio from anything to do with the trim.

If you could verify what the voltage drop is, that may help. You may need heavier wiring for the trim and other accessories at the console. If you can verify a drop under the console, and confirm that there isn't actually a drop at the battery, heavier wiring should cure it. If you're getting a drop at the battery as well, then it may take more to fix it.