Alot of noise

[moretoys]

I just bought a 91 21' Daytona with a 200hp xri on the back. Took it out this weekend and the boat did great, however when it came time to crank the tunes all hell broke loose when I fired the motor up. It made a very loud whining noise that gets worse the longer I leave the radio on. I looked around and checked all the grounds and every things seems ok, it does not matter where the battery switch is. Any input would be appreciated hopefully its not just an outboard thing. Be nice to figure it out before our Havasu trip next month.

[Havasu Hangin']

There's a couple different situations that can make noise. The most common in boats is when the head unit is connected at the dash. The best luck I've had is to isolate the entire system (don't use any of the boat's power or ground wires)...and run 12v+ directly to the Perko.
Your problem sounds like a ground loop (the whining increases with the engine RPM?). If so, isolating the system should solve it.
If you have amps, you can try unplugging the RCAs and see if the noise goes away. If it doesn't, it's the amp wiring. If the noise stops, it's in the head unit.

[moretoys]

Thanks, I disconnected the RCA's and the noise stopped so I ran a power wire to the perko and a ground straight to the battery but it is still doing it, I did notice that whenever I bumped the head unit that it transfered through to the subs, not sure what thats about I have never had that happen before???

[Havasu Hangin']

Thanks, I disconnected the RCA's and the noise stopped so I ran a power wire to the perko and a ground straight to the battery but it is still doing it, I did notice that whenever I bumped the head unit that it transfered through to the subs, not sure what thats about I have never had that happen before???
Maybe the head unit is heading south? Do you have another you could hook up and try?

[moretoys]

It turned out to be the head unit, rewired the power and ground just to make sure and everything is ready to roll, now I just have to figure out what to do for the 4th. Thanks for the help