Topic: Power Problem ....HELP NEEDED!!!!

[calli1]

Ok folks...turning to my electronic friends.  This is not a side image question  ut I thought you could help.  I have a 5 yr od 787c21 Humminbird Unit that I use on the front of my boat.  I was fishing on Monday...unit working fine and all of a sudden once i moved from one place to another, the unit was off.  I checked fuses on water and at home.  Here is what I did and what I found.....  Checked with a volt meter...I use to be in the electrical line of work many yrs ago.....from the battery to the end of the unit power cable.  Was reading 12.2 volts....this is or was between the two little brass pins.  So, how do I know my unit head ( 787c2i ) is acutally working, I slipped it onto my other boat mounting bracket and works fine.  I then took another unit I have on that boat...slid down on the bracket...no working unit.  Like I said....I checked between the two brass pins and would read 12.2 volts.  I even took wiring apart and plugged the power direct into the unti and no luck on either.  What should i do...order a new power cable ?  I have power but could the pin s have shifted down and away from the female side of things.  Another thing I did was bend the brass pins for a more snugg fit.  Please help.  I almost chunked this unit because if the repair fee I saw on the website and ordered another complete system but when I tested on my other boat..worked fine.  Give me some ideas....somehow...someway....the unit(s) aren't getting the power.

[Humminbird_Greg]

This sound like a power (current) restriction problem (loose/dirty connections) to anyone else?

[ITGEEK]

Fully charge and load test your battery.
You may have the voltage, but not enough amperage
to sustain the unit.

[Ddorriety]

I am guessing your unit is connected to your cranking battery. If this is so the most likely problem is a weak battery. When cranking the motor there will be a voltage drop. The weaker the battery the deeper the voltage drop. At the battery the voltage level should be at least 12.6 to indicate a fully charged battery. A voltage of 12.2 at the battery would indicate a battery with less than 50% charge. 

The give away is when you said when you moved it happened. 

[calli1]

Rewired from unit to battery.  No, I have my electronics...one of them anyway on my trolling motor battery and the other...1198 on my craking battery.  Everything is working great now.  Thanks to all for the help.