Depth finder gone mad

[TRZ II]

My humming bird depth finder is going crazy on me. The transducer is tightly fixed to the boat, but the finder goes crazy sometimes reading 400+ ft for 5 min. and then back to zero for 5 min. and then back to normal for 15 min. I can't figure it out, the transducer is not moving but this is happening. Any ideas would be greatly appreciated!

[whitebassman]

this happened to me too.

either the transducer position needs to be adjusted on the back of the boat. or

try increasing the sensitivity of the beam, maybe its having a hard time locking down the bottom. adjust the switchfire setting also (if you have that). Just try playing around with the settings, then if no go, make sure your transducer isn't too loose.

all else fails, call HB.

I had problems last summer, but cross my fingers, haven't yet this spring.

[TRZ II]

I played with the sensitivity. I don't think that was it. I will try to move the transducer. HWere should the transducer be placed?

[CAMAN]

First make sure the battery is good (and by good I mean load tested) and fully charged. If that doesnt help check on HB's HSOforum for any updates on the unit.

[TRZ II]

What does load tested mean? I did seem to get worse after I ran the trolling motor off the same battery?

[CAMAN]

Bring the battery into a full service auto parts store or a place like batteries plus. Ask them to load test it. It is where they put a high amperage load onto the battery and they check to see if the battery can keep up. A bad battery can say it's still good and have full charge under no use, but the moment any amps are pulled from it it dies.

It's also a good idea to seperate a trolling motor from everything else in the boat. TM's are notorious for messing with depth finders and causing bad readings. One battery for TM and one battery for everything else.

Depth finders don't like low power conditions and will show messed up readings when the power has dropped.

[RebelSS]

My Hbird has done the SAME exact thing a couple of times over the years...it was always cured by moving the transducer up or down a tad. If it isn't exactly right, different water conditions such as chop, high waves, etc. will cause it to lose readings/give falde readings.

Also, make sure your connections and plug in is tight and corrossion free, with a good battery ground.

[reddog]

check to see that your max depth window is set at 150, rather than 1500 also.

[TRZ II]

I played with the max depth that did not help. I need a new battery anyway so I will try that. Thanks for all the helpful hints guys!