2003 Yamaha 115 4 stroke. Battery is strong. Trim switch on motor works great. All accessories work. Guages are dead. Ignition Switch does absolutely
nothing. Trim switch on remote does nothing. It was working fine, and then it wasn't. Just like that.

Check the main power wires coming from the alternator under the cowling, headed out to the front for an inline fuse. My '90 Yamaha ProV did the same & it was the fuse holder not making connection or intermittently cutting out. Hope this helps.

Hope it’s a quick fix like a fuse.

One point of failure with all boat wiring is the wiring inside the throttle handle. Years and years of shifting can eventually wear and rub the wiring inside the throttle handle causing a short to ground.

looks like something to do with the white wire or a ground problem

If it’s not a quick fuse fix; my guess is that it’s the red “main power” wire shorting to ground in that it is shared with ignition and gauges.

The other shared line is the yellow wire. But, if it was the yellow wire, some of the gauges would still work.