Topic: side imaging fades out a a depth of 18-20 feet

[mccostlin]

Morning all,

first post here. I searched all over the site the last few days and I cant find an answer to my problem.

I have a 797 c2 and the side imaging and down imaging work fine in under 15ft of water. as soon as I head to deeper water the images fade out to nothing at or about 17-20 ft of water. one I head back shallow it starts working fine again.....I have restored defaults and checked every setting on the unit to inlcude making sure the lower range is on auto.

any thoughts?

Thanks,

[Humminbird_Greg]

Welcome to the Humminbird Side Imaging Forums mccostlin.

This could be due to several different reasons:
- The transducer is getting weak.
- The unit is failing.
- There is not enough power to the unit.

Try cross testing with someone else that has a Humminbird Si model unit (any model will work for the test) but only connect the power and transducer cables for the test.  This will let us know if the problem is on your boat (transducer/power issue) or in the unit.

[mccostlin]

it works on my 898 power/TD, when I first installed it  I had no SI or DI, it was blacked out. I adjusted the TD down a bit and it started working in shallow water......how can I check the voltage? the TD was new when I got the unit last week from a local guy. the power for the unit is hooked up with a scotch lock to one of the aerator pump switches....  my 2D unit worke fine witht the power coming from there.....maybe thats the issue.

thanks for your help.

[Humminbird_Greg]

Test your 797c2 unit on your 898’s transducer and power connection again.  Something has changed since you first got it so we need to figure out if it is something in the unit or if it is elsewhere.

You really need to be able to test both the voltage and the current (power = voltage X current).  You should ditch the scotch locks and run a new set of wires from the 797c2’s power cable all the way back to the battery it is powered from.  Solder all electrical connections, use a new fuse holder, fuse and battery connections.  Doing so will help ensure your unit has the proper power that it needs.  A good quality marine grade twisted copper wire (not solid) in at least a 18 gauge will work best.