# Stereo and gps for a boat wont hold power



## martin p (Feb 20, 2017)

Hi everyone

I removed all my negatives to my bus bar as it was getting old and needed a clean, i have a fusion ms-ip600 stereo and a furano gp-1650wf sounder/chart plotter.

the 2 power cables for the steroe had been connected to the power cable of the sounder, the power lead connecting the stereo and sounder was taped up and not connected.

The negatives from the sounder and stereo were connected to the negative bus bar.

both the sounder and stereo worked, with only the negatives connected, both units are capable of holding memory without battery connection.

Always at start up, the sounder would alarm that internal battery is low and has faied start up test, cancelling the alarm the sounder worked fine, the stereo worked fine too.

i have connected the positives direct to the battery and the negatives direct to the battery and both the stereo and sounder display similar problems.

Using a test light as a lead for the ground terminal and a cable for the positive on the stereo the following happens:
Initial cnnection has the test light at about half wattage, then it goes out after approx 10-15 seconds. When i hit the power on switch for the stereo the lights of the stereo come on for a split second then no pwer, doing this will make the test light repower to half wattage before going out again in the 10-15 second time frame.

The sounder when connected does not light the test light used as a cable, but when i press the on switch of the sounder it will light up for a ssplit second and then nothing, if i attempt to hold the power button on the test light will flicker

I have no idea how these electronics were working with only the negatives connected to the bus bar before, and now that i am trying to wire them correctly the above happens.

Could it be capacitors inside both?
Could they have been running off the internal batteries which were getting a very small charge from the negative connection?

Do they sound like they are cooked showing those symptoms.

I had an auto elec who looked at it initially and he said if they are working dont touch them, he also wired my spot light to my stern light and screwed up a few other things so im not keen on asking him again.

does anyone have any clues or tests i can try? both units have inline fuses and both are intact.


----------



## martin p (Feb 20, 2017)

i tried connections on speakers, power direct to battery, ground direct to battery, both the gps and sounder appear like they dont hold the current to turn on, they both get their screen lights on for a split second and die,
could this be from having the polarity reversed?
if so, is there a typical component that would burn out first, fuses are al intact, a 3 amp fuse on the sounder has not blown.

Anybody got an idea what it could be, cmon, give me something


----------



## Done_Fishin (Oct 10, 2006)

I don't really understand your circuitry but I do vaguely get the impression that you have a boat with Battery where two pieces of equipment had been running normally until such time as you decided to remove the negatives wires from the negative rail leading to your battery. 

Equipment connected to a battery MUST have connections to both sides of the battery, otherwise current cannot flow the the equipment, the equipment cannot function unless there is an alternate Voltage / current source for the power that is needed.

This means that if the only items you touched originally were the negative connections .. and now it no longer works .. most likely you didn't put the negative connections correctly and the positive connections are not obvious. 

Have you checked the battery to see if it is charged ? you say that a spotlight was added to the circuitry .. Does it work when turned on ?? Measure the battery voltage and ensure that it has the correct voltage!

Perhaps the positive connections are via a switch that is no longer in the ON position .. Also if the battery is old .. it may have high internal resistance which would limit the amount of current that the battery can provide .. quite frequently the battery voltage shows OK until a current is taken out at which point the battery voltage drops completely ..


----------

