Help with Battery issues after stereo install

[nola mike]

The diagram that came with the unit states yellow is main, red is accessory, black is ground.

Bt's right, though wondering if we're saying the same thing. By "acc", do you mean switched/ign power? What brand do you have

 

[benpink]

Bt's right, though wondering if we're saying the same thing. By "acc", do you mean switched/ign power? What brand do you have

Yes red is switched power. But I tied it into the main wire so it’s always hot. I don’t see how that could cause the problem with the negative wire on the battery though. It just acts like you have the switch on all the time.

 

[benpink]

Alright well I believe the mystery maybe figured out... I hooked everything up again this morning and had a buddy verify that in theory I was wired correctly. Started the boat and radio all on the same battery and have zero issues. So all is good.
Now the therory for the original smoke is that the negative main motor harness wire and the negative stereo wire had a loose connection with some space between them, and when the motor drew more current to start, there was a spark jumping between them thus melting the plastic of the wires. This is our best theory. Open to any other ideas.
Thanks for all the help and ideas. This is a great forum.

 

[nola mike]

Now the therory for the original smoke is that the negative main motor harness wire and the negative stereo wire had a loose connection with some space between them, and when the motor drew more current to start, there was a spark jumping between them thus melting the plastic of the wires. This is our best theory. Open to any other ideas.
Thanks for all the help and ideas. This is a great forum.

Exposed neg wires wouldn't do that, but if you had an exposed pos in proximity to an exposed neg, that certainly would. You'd have a short to voltage on the neg wire, as mentioned in previous posts. Also, with the engine running you'd have some vibration moving the wires around. Glad you got it sorted, though that problem with the lawnmower battery still doesn't make sense.

 

[benpink]

Exposed neg wires wouldn't do that, but if you had an exposed pos in proximity to an exposed neg, that certainly would. You'd have a short to voltage on the neg wire, as mentioned in previous posts. Also, with the engine running you'd have some vibration moving the wires around. Glad you got it sorted, though that problem with the lawnmower battery still doesn't make sense.

Interesting. Well definitely not a red wire anywhere near the black wires. It really is a mystery why it happened in the first place because nothing is really changed and now it works fine. Electricity is weird.

 

[dingbat]

14Ga will carry 15 amps safely.

Define safely…wire doesn’t catch fire?
Voltage drops are a huge concern on boats

 

[RBoyd1971]

Define safely…wire doesn’t catch fire?
Voltage drops are a huge concern on boats

I know y'all know this, but I'll say it anyway. It depends on the length of the wire to and from whatever is being powered. The longer the wire the less current it can carry without to much voltage drop. Heck you can power less sensitive equipment with 12 amps in 16 ga wire if the total run is 20 ft or less.

 

[poconojoe]

Define safely…wire doesn’t catch fire?
Voltage drops are a huge concern on boats

I understand that we are speaking very generally here.

There are charts for this.

Yes, a 14 gauge wire can handle 15 amps as a general rule, but....

There are many variables, of course and the wire needs to be derated accordingly and a larger gauge may be needed.

Voltage, amperage draw, wire size, wire length, type of insulation, type of metal the actual wire is made of, stranded vs solid, wire ran through some type of conduit as verses free air, how packed a conduit might be.

Land based wiring has many variables. Copper, copper clad, aluminum conductors, stranded or solid.
THHN, THWN, TW, and many more types of insulation. Each rated for intended environments (temperature, moisture, etc).

And...as most of us know...boat wire is very specific and tinned throughout it's length.

It's best to consult a marine wiring amperage rating chart and only use marine rated wiring.