Need a little help from those that are more knowledgeable with regard to the AUX jack on the radio.

I have a 2005 EG Classic with the stock am/fm/cd & AUC Jack.

I use the appropriate cable to plug into the ear jack of the gps unit and put the other end into the AUX jack.

When the bike is off, the sound works just fine thru the stereo, but when the bike is running there is quite a bit of interference and static. This is the same cable that I use for my IPOD & Other MP3 and never have the same issue.

Is there some sort of in line filter or perhaps a preferred cable that should be used when using the GPS?

Appreciate the help.

Thank you,