GPS and. Starting

GasCan II

Petty Officer 1st Class
Joined
Jul 15, 2010
Messages
281
After starting the boat and turning on the GPS chart plotter, if I turn the boat off ,when restarting boat the GPS chart plotter shuts down ! Is it wired wrong ?
Thanks for any help.
 

Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,740
They can also shut down if the voltage drops too much.
Check and clean your connections.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Starters draw a heavy current load. Watch your voltmeter as you crank the engine. You will see a sharp voltage drop especially if you have a weak or under sized battery.
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,762
Todays more sophisticated electronics are best run off a separate battery if possible.

If that can't be done, a power line connected directly to the battery (with fuse) is the next best option.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,423
a large capacitor across the power leads and an isolation diode would help with the voltage dip effect on your GPS as well. or simply start the motor before starting the electronics.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,367
Todays more sophisticated electronics are best run off a separate battery if possible.

There is no need for a seperate battery except to counter the effects of a deficiency down stream.

Today's auto ranging power supplies are better than ever. Decent supplies can push anywhere from -30% to +50% of nominal voltage.

The -30% reprints 10 times the allowed 3% voltage drop specified by good electrical protocol.

Loose or corroded wiring to GPS or starter
Under sized wiring to GPS or starter
Weak or undersized battery
Defective starter

The cheap, In-line fuse holders supplied on most units are notorious for causing "brown out" issues. I replace OEM fuse holders with a good, sealed fuse holders as part of my initial installation
 
Last edited:

JASinIL2006

Vice Admiral
Joined
Feb 10, 2012
Messages
5,725
After starting the boat and turning on the GPS chart plotter, if I turn the boat off ,when restarting boat the GPS chart plotter shuts down ! Is it wired wrong ?
Thanks for any help.

My GPS/fish finder used to do this as well. It was especially a pain because I use the GPS speedometer function to monitor speed while pulling the kids on a tube. Every time we shut down the engine to change riders, I had to restart the GPS.

I ended up installing a second battery to use for non-starting functions (stereo, GPS/fishfinder, etc.) and it solved the problem. I bought a Blue Sea Add-a-Battery kit so both batteries charge automatically but are separated for their different purposes.
 
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