Help with Battery issues after stereo install

[benpink]

I installed a new stereo and speakers on our barge today. I ran wires directly from the battery with an inline 10amp fuse to the stereo. Positive and negative. When I initially hooked everything up, the stereo powered on and ran just fine. When I started the motor however, the negative terminal started sparking and melted the wires on the negative terminal. I unhooked the stereo, and the motor started and ran fine. I went to reattach the negative wire from the stereo and noticed it started sparking slightly. Now the stereo won’t Turn back on. The 10amp inline fuse is not tripped. The only thing I can think is that the 14 gauge wire I used to run to the stereo couldn’t handle the increased load from the motor circuit once the motor was started?

I’m stumped and really don’t want to pull all the wiring out as it took me hours to install. Anyone have any suggestions?

 

[nola mike]

I installed a new stereo and speakers on our barge today. I ran wires directly from the battery with an inline 10amp fuse to the stereo. Positive and negative. When I initially hooked everything up, the stereo powered on and ran just fine. When I started the motor however, the negative terminal started sparking and melted the wires on the negative terminal. I unhooked the stereo, and the motor started and ran fine. I went to reattach the negative wire from the stereo and noticed it started sparking slightly. Now the stereo won’t Turn back on. The 10amp inline fuse is not tripped. The only thing I can think is that the 14 gauge wire I used to run to the stereo couldn’t handle the increased load from the motor circuit once the motor was started?

I’m stumped and really don’t want to pull all the wiring out as it took me hours to install. Anyone have any suggestions?

Your negative wire is getting positive voltage from somewhere. If it's wired like you say (and correctly at the stereo) I can't think of how that could happen. The stereo may have a few positive inputs (main power, remote wire, memory power). I'd try disconnecting everything else first. Also, your stereo probably has a fuse on it. Hopefully that's blown and you didn't fry the whole unit.

 

[benpink]

The stereo has main power(yellow), ACC power (red), and ground (black). I couldn’t get switched power to the red, so I tied it in with the yellow so that the unit always has power. I just use the power button on the unit to turn off when I’m done. Could this be causing the problem? Seems like it makes sense and shouldn’t be an issue. I just ran the wires yesterday and there’s only two of them nice and clean. So I don’t see how the power could be getting switched around as you say.

 

[alldodge]

The stereo has main power(yellow), ACC power (red),

I would bet Red is main and Yellow is ACC

 

[Horigan]

Attach the red wire to the battery and then check voltage on the black negative wire with a meter (not connected to battery) to see if the stereo has an internal short.

 

[nola mike]

I would bet Red is main and Yellow is ACC

For whatever reason, yellow is usually battery and red acc. That said, clearly something is wired wrong somewhere. I'd try disconnecting everything else and verify that there isn't voltage present in your black wire when the others are connected to pos

 

[dingbat]

First off, what motor are we dealing with?

If I understand correctly:
You ran dedicated ground and power wires directly from the battery to the radio
You tied main power and "memory" wire together
You have a burnt wire on negative terminal post.

14 gauge wire is rated to 5 amps - 10 amp fuse (in use) = melted wire - Having said that, it shouldn't have been a problem. Radio's typically don't draw more than a couple of amps.

Pretty obvious your new negative wire is shorted to hot...somewhere.

Guessing starting the motor is just coincidence unless you have a problem with your charging system. A power surge could easily burn components in the radio, shorting power to ground internally.

Disconnect radio and check continuity between radio's red (+) power lead and ground (-) lead through the radio. In theory, the red circuit should be an closed circuit with radio on. Open circuit with radio off.

 

[benpink]

So riddle me this. I decided to try an experiment. Took a completely separate 12v battery up in the workshop away from the boat. Ran new red from the positive, and new black from the negative. Tied the main power and acc power together and connected to the battery. I go to closed the circuit with the negative and it’s blowing a fuse instantly. This is set up exactly how I did it yesterday when the radio turned on and worked for 30 min. What am I doing wrong?? I am using a 12v battery, 14 gauge wire, 10 amp fuses. Nothing changed from my last setup when it turned on and worked, yet now I’m getting an instant blown fuse. I’m about to give up.

 

[briangcc]

Head Unit out on the bench and its blowing fuses? It's shorted internally or in the wiring somewhere.

Is there a pigtail coming out of the head unit with a bunch of wires for output, input, power, etc? If so, I'd check that carefully to see if the wires melted there. If that's good, you probably have an internal short in the head unit....which may/may not be covered by the manufacturer.

Back to what happened initially....something got shorted for a LONG period of time to melt wiring. Ask me how I know....

 

[benpink]

Well the inline fuse was blowing on the bench before the power got to the head unit. That’s what I can’t figure out. There can’t be a short because the wiring is right in front of me on the bench and I just set it up. The took a multimeter to each of the wires in the harness and they all show the correct voltage. But once the unit is plugged in, pop. Also I went and got a new head unit just to make sure that wasn’t the problem. So the issue is why is this new battery blowing fuses??

 

[nola mike]

Well the inline fuse was blowing on the bench before the power got to the head unit.

What do you mean "before the power got to the headunit"?

Also I went and got a new head unit just to make sure that wasn’t the problem. So the issue is why is this new battery blowing fuses??

The new head unit is doing the same thing?

 

[benpink]

The inline fuse from the battery is popping thus the power isn’t getting to the unit. And correct the new head unit is experiencing the same problem. I’m using a 12v battery used for a lawn mower so maybe that is the problem. Although I thought all 12v batteries are the same.

 

[benpink]

I hooked the new head into back into the same wiring in the barge as before. It is now working and playing music. But I haven’t attempted to start the motor which is what caused the previous problem. So now I’m looking for ideas to keep my current setup but not cause any melted wires when I start the motor. This battery is a marine grade 12v battery that’s been on the boat a year or so.

 

[nola mike]

If the wiring is as you described, and there are no breaks in the wire that could short it to the main wiring, I can't see how they're related. But like I said before, you can disconnect the negative for the radio, start the boat, measure voltage across your battery to make sure you're not getting something wild from your alt, and measure voltage from the radio negative to battery negative/ground with it still disconnected. You should get 0v.

 

[nola mike]

The inline fuse from the battery is popping thus the power isn’t getting to the unit. And correct the new head unit is experiencing the same problem. I’m using a 12v battery used for a lawn mower so maybe that is the problem. Although I thought all 12v batteries are the same.

No, that doesn't mean power isn't getting to the head unit. It means that too much power is getting to/through the head unit. Yes, lawnmower battery should be fine. Wait, so new HU popping fuses on the lawnmower battery but not on the marine battery?

 

[benpink]

No, that doesn't mean power isn't getting to the head unit. It means that too much power is getting to/through the head unit. Yes, lawnmower battery should be fine. Wait, so new HU popping fuses on the lawnmower battery but not on the marine battery?

This is correct. It was only blowing fuses when hooked up to the lawn mower battery. Now that it is back hooked up to the original wiring on the boat it is working fine. But I haven’t attempted to start the motor yet, which 100% caused the negative battery terminal all wires connected to it to start smoking last time. So should I get another marine battery and just use that one to only power to stereo? I wouldn’t mind having two batteries onboard.

 

[Bt Doctur]

14Ga will carry 15 amps safely. Almost all electronics and stereo`s are Red, main power using a separate switch, Yellow is always on ,it is the memory

 

[nola mike]

This is correct. It was only blowing fuses when hooked up to the lawn mower battery. Now that it is back hooked up to the original wiring on the boat it is working fine. But I haven’t attempted to start the motor yet, which 100% caused the negative battery terminal all wires connected to it to start smoking last time. So should I get another marine battery and just use that one to only power to stereo? I wouldn’t mind having two batteries onboard.

Beats me. None of this makes sense. If you have separate wiring to the HU in the boat, I'm going to double down and say that unless there's a problem within the HU or a short in the negative wiring, this can't happen. A current spike in the boat wiring should blow the inline fuse, or the HU fuse. I'd still be interested in seeing if you have any voltage in the HU neg with it disconnected from the battery and the engine running.

 

[benpink]

14Ga will carry 15 amps safely. Almost all electronics and stereo`s are Red, main power using a separate switch, Yellow is always on ,it is the memory

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

 

[benpink]

Beats me. None of this makes sense. If you have separate wiring to the HU in the boat, I'm going to double down and say that unless there's a problem within the HU or a short in the negative wiring, this can't happen. A current spike in the boat wiring should blow the inline fuse, or the HU fuse. I'd still be interested in seeing if you have any voltage in the HU neg with it disconnected from the battery and the engine running.

I am going to work on it tomorrow. I’ll check the negative with it disconnected and see what it says. I think I’m going to get another battery and create a separate system so it’s not affected by the motor running, even though it shouldn’t be now but I can’t figure out why it happened.