# electrical question



## jacobd08 (Aug 24, 2020)

Hello everyone,

I am a newbie to both this forum and as a boat owner. I am excited to be here and hope to learn a lot. I come with questions!

I recently purchased a used 17' Alweld aluminum boat and immediately started tinkering. The previous owner had several instruments messily wire together. I decided to redo the wiring and ran separate positive and negative wires from the front nav. light, the back nav. light, and bow mounted spotlight to a rocker panel. I stalled a negative bus bar between the battery and the rocker panel. The positive leads on all instruments connect directly to the rocker panel and the negative leads connect to the negative bus bar. All lights work fine when their corresponding switch is flipped. However, the spotlight now makes a very loud high-pitched whistling noise while on. I have searched the internet and this forum to try and find answers with no luck. Does anyone have any ideas? Thanks


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## DaleH (Aug 24, 2020)

Small shorts in wires or carbon/corrosion build-up on electrical contacts can lead to similar 'on/off' striking and cause electrical humming or buzzing. Clean everything well or use NEW connectors. Also do a resistance check if you used old wires, as maybe one is corroded inside.

Are the wires used too small? You need to measure the run BOTH ways and that total length is used to address the AWG needed for the amp draw. If the spotlight rating is in watts, divide it by 12.6 (nominal VDC) to get the amp draw. 

.


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## jacobd08 (Aug 24, 2020)

Thanks for your reply. I did use the old wires for the spotlights, which resembled lamp cord. When I touched the positive and negative leads directly to the battery the lights came on with no sound so I went ahead and hooked them up to the rocker panel and bus bar. I did notice the wires used to connect the spot lights to the rocker panel are larger than those on the lights and rocker panel, but not by much, maybe 16 gauge on the rocker panel and lights and 12 on the wires connecting them. Also, the rocker panel uses 3 15A fuses which seems to be appropriate after looking at the chart you provided.


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## DaleH (Aug 24, 2020)

:shock: 'Lamp cord' usually equates to only 18 AWG marine wire, as it is a much softer copper wire construction (so it may not have the ampacity, i.e., capability to transmit electrons). I myself never use household wiring products in boats ...


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## jacobd08 (Aug 24, 2020)

Yes , I too thought this was strange, but gave the previous owner (an intelligent friend of mine) the benefit of the doubt. However, it is at least 14 gauge wire so maybe it just looks like lamp cord. Also, it did not have clearly marked positive or negative sides, just two wires separately molded into black wire plastic. It confuses me that it worked fine when connected straight to the battery, though. It would not be hard to redo the wiring, but I am not sure if that is the issue being it worked fine when connected directly to the battery.


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## jacobd08 (Aug 24, 2020)

Dale, I just reread your last post and realized I missed the part of lamp cord not being constructed at the same quality as marine wire. I may go ahead and replace the wire in question. This evening, I connect the spotlight negative wire directly to the battery and still heard the high pitched noise. Maybe this means the issue is at the rocker panel connection. Maybe a little more tinkering will expose the issue. Thanks for the feedback.


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## CedarRiverScooter (Aug 25, 2020)

Sounds like the switch has bad contacts inside it.


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## jacobd08 (Aug 25, 2020)

CedarRiverScooter, surely that has to be the issue. If not, why would it work fine when wired straight to the battery. Also, when I wired the negative lead straight to the battery and left the positive wired to the rocker panel it still made the high pitched noise. Unfortunately, the lights are old and I have no idea the make or model to look them up. I will redo the connection tonight and see if it helps.


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## DaleH (Aug 25, 2020)

Resistance check the switch/rocker panel ...


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## jacobd08 (Aug 25, 2020)

DaleH, would you mind explaining how to check the resistance? I do have a multimeter.


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## DaleH (Aug 25, 2020)

jacobd08 said:


> ... would you mind explaining how to check the resistance? I do have a multimeter.


Too much to write ... get manual to your specific model online, read below or see link below for analog or digital models, making sure to only check circuits that are not powered/energized.

_"Set your multimeter to the highest resistance range available. The resistance function is usually denoted by the unit symbol for resistance: the Greek letter omega (Ω), or sometimes by the word “ohms.” Touch the two test probes of your meter together. When you do, the meter should register 0 ohms of resistance."_

https://www.electronics-notes.com/articles/test-methods/meters/multimeter-resistance-measurement.php


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## jacobd08 (Aug 25, 2020)

Thanks! I will read into this and check this afternoon.


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## LDUBS (Aug 26, 2020)

Could it be loose terminal connection(s) at the switch?


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## jacobd08 (Sep 2, 2020)

LDUBS, it could be loose. I am still trying to figure it out. I am going to check the resistance first. There are 3 positive wires running from the rocker panel spliced into a single wire to the battery. I am going to redo that splice in case that is the issue.


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## DaleH (Sep 2, 2020)

jacobd08 said:


> There are 3 positive wires running from the rocker panel spliced into a single wire to the battery.


Huh :?: ? On my boats I have 1 (fused) main +Pos heavy AWG wire from the battery up to the panel, that then powers the panel ... why would you ever have 3 on the battery side?


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## LDUBS (Sep 2, 2020)

IDK. What I visualize is someone spliced three wires to the positive from the battery for each of three switches.


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## DaleH (Sep 2, 2020)

LDUBS said:


> IDK. What I visualize is someone spliced three wires to the positive from the battery for each of three switches.


Yeah, I don't get it ...  ... substitute 'fuse panel' below with a switched panel and presto! However, _I do understand _that this is all new to those who have never done their own. But, we're here to help!
.


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## LDUBS (Sep 2, 2020)

That wiring diagram is a big help to us "rookies". I'm not the one with the original question, but thanks!


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## jacobd08 (Sep 4, 2020)

The panel itself has 3 positive wires, each with its own inline fuse. I spliced those 3 positive wires into 1 wire and ran to the battery.

I have attached a wiring diagram of the panel.(Hopefully it attached)


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## eeshaw (Sep 4, 2020)

I know the switch panel in my boat has two +12v leads, each feeding four switches.


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## DaleH (Sep 4, 2020)

Those fuses as shown on that panel are supposed to be between the panel switch or connection and the item or the load! 

Look at my diagram for the main feed, that is already fused within 8” from the battery, per ABYC guidelines. You do not need additional fuses on the other side.

IMHO, whomever wired that panel up sure made an absolute mess of it ...


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## jacobd08 (Sep 4, 2020)

This is how the panel came wired from the factory. It was pretty cheap!


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## jacobd08 (Sep 4, 2020)

Each one of the red lines at the bottoms are spade ends where the instruments connect. So I guess the fuses are between the switch and battery.


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## LDUBS (Sep 10, 2020)

Curious about the outcome. Any update? Thanks!


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## jacobd08 (Sep 10, 2020)

Everything is still working fine. The high-pitched noise has become more apparent in the light bar itself. Where as before, you really couldn't pin point where it was coming from. I did a quick google search for high pitch electrical noise in light bars and it seems to be a common problem. I am sure these are cheap light bars and maybe its just an issue with the construction. However, I did not have this issue until I connected it to the rocker panel. I am sure DaleH is on to something with resistance. Or possibly the switch has a poor connection.


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## LDUBS (Sep 10, 2020)

Thanks Jacobd. I learn a lot from this site just reading about issues.


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## Gary Roe (Feb 25, 2021)

I use Bigsun spotlight but I lost my charging cord. where can I get another?


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## InSaneFisherMan (Feb 26, 2021)

Gary Roe said:


> I use Bigsun spotlight but I lost my charging cord. where can I get another?



If it is a SLA battery, you can find them on Amazon or eBay, If a lithium battery, you will probably have to contact the manufacturer to get the correct charger.


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## Gary Roe (Mar 4, 2021)

InSaneFisherMan said:


> Gary Roe said:
> 
> 
> > I use Bigsun spotlight but I lost my charging cord. where can I get another?
> ...



I don't know where to get one but here is the info. from mine: AC ADAPTOR Model: BS0422000 Input: 100V-240V 50/60 Hz Ouput: 4.2VDC1.5A


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## InSaneFisherMan (Mar 4, 2021)

Gary Roe said:


> InSaneFisherMan said:
> 
> 
> > Gary Roe said:
> ...



Plenty of 1a and 2a on Amazon, but Lithium batteries, I wouldn’t recommend.

There is a least one on eBay or you can try the company:

E-mail: [email protected]
http://ibigsun.com/


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