Lowrance structure scan problem

I have recently installed a Lowrance HDS 7 Gen 2 with structure scan on a pontoon boat. The transducer is mounted on the rear of the port side pontoon. The unit works great sometimes but it will suddenly start scrolling to fast and reporting that the water is 5 feet deep no matter how deep the water actually is. I can switch to 455 frequency and back to 800 and it will work sometimes. Other times I just have to stop the boat and wait as long as 10-15 minutes before it will begin to read correctly again. I tried turning the motor off and getting it to reset and that did not help. I even tried resetting the unit back to factory settings and that does not work. I had another lowrance, depth finder only, in the dash and I thought there might be some interference from it so I unhooked it but the problem did not go away. I don’t understand what makes it stop working and what makes it start working again. It is really frustrating because when it is working it is awesome. Has anyone else had this same problem?

I thought I heard that a right turning prop the transducer should be mounted on the starboard side of the motor and at least 15″ away..

Make sure the transducer is really tightley mounted. I just moved my HDS system and LSS-1 over to my new boat this spring and when on the new boat I kept getting static every once in a while and would sometimes stay for 10-15 minutes.

Would shut everything down including motor, trolling motors, other graphs, even disconnected my other graphs from the network and static would remain. Checked all my wire connestions and even replaced eithernet cables.

All I had to do was make sure the “Pivot” bolts were really tight and added 2 more screws holding the bracket to the boat so there is now 4 screws and static has been gone ever since. Mine must have been picking up a vibtation but it was really weird how I could shut everything down and problem would not go away for quite a while.

Good luck with Lowrance Tech Support! I am still waiting to hear back from them!