Installing XM Radio, losing AM reception...

[JDP]

I am installing XM radio into my boat.

When I connect the power supply for the reciever I lose nearly 100% of my AM radio reception.
I have tried an open terminal in fuse box, tapping into other pos and neg wires under dash, as well as testing a connection to a trolling motor battery. No improvement.

The second I disconnect my AM radio works like a dream.

I would like to keep AM radio for local weather updates,etc.

Any suggestions how I might solve?



Thanks.

JDP