Boat Wiring questions

kbrown5897

Recruit
Joined
Apr 13, 2012
Messages
3
Hey all,

I currently have had an issue with my HDS7 powering off when starting my boat. Sometimes it will, sometimes it wont. The battery is good and brand new. I took a voltmeter to the battery and it read 12.7-13 volts. The HDS7 and my x125 is wired to the accessory/fuse box under the console. If I turn on the X125 and take a voltage reading it shows 12.75 volts. If I turn on that HDS7, it will drop down to about 12 volts. I am thinking the wiring up from the motor to the fuse box is too small, not allowing enough current flow???

How are the wires brought into the engine compartment on an older 1990 evinrude?? I have only 1 set of cables off the battery and into the engine compartment. I think I want to try replace the wiring from the engine up to the accessory block. While in the process of this, I have thought about adding another deep cycle battery and just running the new wires from the accessory/fuse block directly to that new battery, and have just the starting battery hooked directly to the motor and thats it. I planned on buying a 4 position blue sea switch that I could tie both into, just incase.

How would I go about disconnecting the proper wires and re-routing them? I could ohm out the wire from under the fuse block until I find the correct one? How big of a project do you think this would be, and will I have to probably wire nut or cap off the wires in the engine compartment??

All information is appreciated.

Thanks
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: Boat Wiring questions

I do not know what a HDS7 or an X125 are, but I presume they are electronic devices of some kind. The wiring that carries +12VDC from the ign switch is not designed to power anything more than a couple of gauges.

I therefore recommend you pull a power and ground wire of the proper gauge from the battery to a fuse or breaker panel. I like to wire everything thru a single switch, so I do not leave anything on, when I leave the boat.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Boat Wiring questions

There are two electrical systems on a boat. The harness that runs from an outboard to the control box and helm is the "Engine system" and is NOT intended to power the fuse panel or any other high current draw items. The "A" (accessory) termiinal on the ignition switch is intended to power ONLY the instruments.

There is normally a second pair of red & black wires (#10 or #8) that run through a 20/30 amp breaker at the battery to power the fuse/circuit breaker panel. This is the "house or boat system). So the long and short of this is yes -- you have too much current draw for the circuit feeding these items.

You need to determine where the "feed" to the fuse panel is coming from. Disconnect that connection. That feed will not be inside the engine so disconnect NOTHING at the engine. Run the new pair of wires to the panel and the ground buss at the helm.
 
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