Lowrance Elite 5 HDI fish finder won't display the speed of the boat when trolling. The display reads 0.00 mph.

Question edited for a lot more clarity. All question need FULL 'make model (what it is)'.
Question moved from 'Power Computers' to Lowrance.

Your problem is in the boat. You either have a bad electrical connection, or a bad connection TO the transducer or the transducer itself is faulty. You can return the transducer under warranty or return it for testing. It is unlikely to be the internal memory IMO.

Others report the same issue

https://www.thehulltruth.com/marine-electronics-forum/614638-lowrance-elite-7-hdi-randomly-restarts.html

Have you tried a Hard Reset.

To connect your Lowrance Hook 7 fish finder to your Minn Kota trolling motor with Universal Sonar 2, you will need the MKR-US2-10 adapter cable. This cable is specifically designed for connecting Lowrance and other fish finders to Minn Kota motors with Universal Sonar 2 technology

Hey Robert,
the blinking is usually the result of the transducer losing contact with the water..
As far as the screen getting hot.. that is not good.. do you have this unit mounted in dash? It needs some ~cooling.. just some airflow..
http://www.lowrance.com/Root/Lowrance-Documents/US/ELITE-5-7_HDI_OM_EN_988-10647-001_w.pdf

Sounds like you do not have your transducer connected.
You will know it is working if you have a bottom sounding. If you have a bottom sounding (depth reading) and it is correct then you may have to fine tune the finder to see the fish.
I have the same finder on my boat. http://njsaltfish.com/index.php/captainsfocus?sid=61

Just type this into your browser's searchbox. manualslib.com/manual/292954/Lowrance-Elite-5-Dsi.html
You should be able to pull up the manual there.I just did. Garcuda

Mine was doing the same thing. Hold the plus and minus button at the same time and hit the power button

Try this,, http://www.lowrance.com/Root/Lowrance-Documents/US/ELITE-5-7_HDI_OM_EN_988-10647-001_w.pdf

Hey Anon
The transducer installation is more important than anything.. next to correct wiring! You must make sure the mounting is good,,, if its outside the hull, make sure its sitting 1/16th below the hull with no obstructions.. if its inside the hull, the medium you used to fix the puck to the hull must be porosity free and the puck sitting as level with the WATER as possible..
Now, take the manual to the lake with you and DO NOTHING but read the manual and apply what you read to the unit,,, read -repeat - read-repeat.. forget about fishing... now read-repeat and learn... IF nothing seems to be reading correctly.. its probably the transducer installation.. YOU DID use a/the transducer specifically for this unit!!

False fish readings are commonly caused by electrical interference such as alternator noise, and by air bubbles flowing across transducer.

For starters make sure your fishfinder is on an independent circuit and not on one powered by your ignition switch. In other words, you should be able to turn your fishfinder on, even though the engine is turned off. Ideally the fishfinder should be wired directly to the battery with an in line fuse.

Try running the boat at a speed slightly higher than trolling speed, then kill the engine, as the boat slows down to trolling speed do you still see false echos? If yes then the problem probably lies with how the transducer is mounted, or where it is located on the hull.

If you don't see the false echos when the engine is off, it may be necessary to reroute the transducer cable to keep it away from the boat's ignition wires. You can get transducer extension cables if necessary. Also there are filters that you can buy that suppress alternator noise buy attaching between the battery and the engine.

Another common cause of false echos from electrical interference is a transducer cable that has been cut and spliced.

I hope this information helps. Please reply if you have any questions about my response.