Re-wire help

[455Rocket]

I just acquired a Carrera 205 that has its share of stereo problems...
It came with a bitchen Alpine head unit, 4 Blaupunkt speakers and an amp (haven't seen what kind yet)
When the blower, bilge pump or ign. is on I get tons of interference... can't hear a damn thing but screeching... I was told that I need to run shielded wire on the amp to get rid of this problem... I'm also gonna install a MSD ign. filter I have laying around to make sure...
Is this really the case, and what wire is best? Any other suggestions while I have the interior gutted?
Thanks.

[Havasu Hangin']

I'd try upgrading (and isolating) to a big-ass ground and power wire. It's been my experience that noise coming from the dash is usually because someone was lazy and used the stock power and ground wires.

[OldYeller]

you may want to run dedicated power and grounds to the stereo equipment to reduce any problems from coming from the existing boat wiring.