Fish Finder FVC 663



This finder is a dual frequency unit. The high frequency works fine but the low frequency has been giving me problems. It sometimes does not work at all and other times it will only work down to 200 to 250 feet. (It use to work great to 1000 feet)Not sure if I have a transducer problem or a problem with the unit or a wiring problem. Not to many people around here that work on them.
Any suggestions??
Thank you for your question. If you can, make sure the face of the transducer is clean and free of growth. Next I would double check to make sure that the transducer plug is clean and free from corrosion. After that you will either need to take the sounder into a dealer to have it bench tested or get another transducer to hang over the side of the vessel for a comparison.

Thanks for the reply, I will either go on the grid or have a diver check the face of the transducer. I can easily check the other two items.

I have a 12 year old Furuno fish finder (600L). It is acting just as you describe.

What did you determine was the problem?