Electric problem

[bourqueda]

Hi,

I guess I have a ground problem on my boat, nav light, livewell pump and other stuff dosen't run, RPM dosen't run, When I put the ignition On, the fuel gauge go to empty and when I turn the ign off guage fuel go to the good place

the 2 pins connectors for the nav light, I suppose have one pin neg and one pin pos, when I test it with a volt meter, one on my negative battery pole and the other on the pin, I have 12,5v on each pins....like 2 pins is positive

I have a battery selector on the boat

Any suggestions to begins my search?

Thank you

Dany

[Rip Bass]

It does sound like a ground issue. Start at the battery,make sure all the ground wires on the battery are clean and tight and make sure there is no corrosion in the terminals on the wires. There should be a ground buss bar under the dash. Do the same with that,ensure all wires and connections are clean and corrosion free. Last thing would be a broken ground wire and that will require a lot of tracing wires to find unless the break is at the battery or console.

[mcgaff1]

This is a great tool for tracking down bad grounds, no power issues. https://www.powerprobe.com/web-store-1

I have used it countless times.

[billnorman1]

What are you grounding the meter negative lead to?

[wmitch2]

Sounds like your looking for a ground wire. First check ALL your fuses, and the breaker. Then Start by checking the Ohms reading on a meter. connect a wire to the Neg side of the battery long enough to reach the drivers console. Connect the black lead to this wire, set the meter on 20ohms and then touch the bus bar with the red lead. there should be a 0 reading on the meter. If not, then there is a short or bad connection between the battery and the bus bar. You'll have to check the wire to find that short. Sometimes it's just a loose or dirty connection and sometimes you just have to run a new wire. If that connection is good, then you'll have to check each component that is not working to find the short, not difficult, just time consuming.

[BroWhoop]

Use a test light, it will put a load on the circuit your testing. Your meter may or may not. Actually you should use both depending on how your using them and the knowledge of circuits and your meter. It does sound like a grounding issue!

[Jonestrollingmotor]

Yes, if you're putting the ground side of the meter on the ground battery post, every wire you touch (positive or negative) that has voltage going throuh it will/should read battery voltage (or a lesser voltage to show the voltage drop) -- unless there is a diode blocking it somewhere. this is because your reading through the light/appliance.
As for where to start the search. I like to start with the switch and follow the voltage. I would also suggest looking/removing/cleaning all the visiable grounds that you find. Finally, I would suggest staying away from the ignition switch until the last resort. You will also need a basic understanding of DC electric and from the statement of "I have 12,5v on each pins....like 2 pins is positive" I don't believe you have that understanding -- in which case I would suggest you find someone that does and can be hands on.
John

[bourqueda]

ok thanks to all, I will continue my test tonight and I'll give you the answer :)

[DrewFlu33]

"It's always the ground" is what you always hear, and it's almost always true. It still doesn't make it any more fun to trace down. Good luck!!

[bourqueda]

Electricy when you see the wire and you have de place to work it's very cool, but is not the case in a boat hahahaha

[bourqueda]

Have you an idea where I can find the central ground for all wires, the neg buss?

[billnorman1]

If you have a fiberglass boat, clamp the negative voltmeter lead to the negative battery post. I would use a car jumper cable clamped to it and the other end used for a ground. Moving around the boat your meter leads will be too short.

[bourqueda]

ok but all accessoirie is ground somewhere, but where, like nav light or RPM or fuel gauge
If I have a bad ground I need to know where I can find the master ground

[ChampioNman]

Check your negative battery post and make sure the nut is tight. No wing nuts.

[skeeter91]

for what its worth, i do a good bit of electrical in my shop. ive seen a couple of different ways grounds are tied together(from factory) and many of them are very questionable! im not going to call out boat brands by how shitty the factory wiring is due to the fan boys! what make, model, year is the boat? do you see wire nuts or the blue "quick splice" connectors anywhere? how many wires are connected to your battery(accessory leads + or -)? are there butt splice connectors that are not the heat-shrink type or have it around them? there should be absolutly NO accessories spliced to the main engine harness other than the 12volt to the dash. its actually alot easier to pull all the hacked up crap out and use a weather proof fuse box and just run new wire!depends alot on year of the boat and brand, for me anyway!

[bourqueda]

I guess I'll do that, brand new wire

[Jonestrollingmotor]

ok but all accessoirie is ground somewhere, but where, like nav light or RPM or fuel gauge
If I have a bad ground I need to know where I can find the master ground

If the boat has a fuse box, sometimes there is a connection there for the master grounds and appliance grounds to connect. Pumps are usually grounded either straight to the battery or on a ground buss strip located on the transom of the boat (Basscat does this).
This part of the initial post "I guess I have a ground problem on my boat, nav light, livewell pump and other stuff dosen't run, RPM dosen't run, When I put the ignition On, the fuel gauge go to empty and when I turn the ign off guage fuel go to the good place" suggest different issues. The tach is through the outboard wiring, while the other appliance uses stand alone wiring. If none of these (pumps, lights (you say nav light, how about the anchor light), and what is "other stuff") is not working, that suggest a master fuse or breaker, or even a bad master switch instead of a ground issue. You should disconnect from the system, one appliance at a time, wire direct to it and make sure it works, then trace the wires back to the power source.
John

[skeeter91]

^WHAT HE SAID!

[billnorman1]

If you have a fiberglass boat, clamp the negative voltmeter lead to the negative battery post. I would use a car jumper cable clamped to it and the other end used for a ground. Moving around the boat your meter leads will be too short.

What I'm saying is if you are going to use a voltmeter to troubleshoot, you need a ground zero volt reference. That's why you should use the minus battery post. If you find you have voltage on grounds in the boat, then you know you have a ground issue. Since so much stuff doesn't work, you may easily have a ground wire off at the battery.

[Jonestrollingmotor]

What I'm saying is if you are going to use a voltmeter to troubleshoot, you need a ground zero volt reference. That's why you should use the minus battery post. If you find you have voltage on grounds in the boat, then you know you have a ground issue. Since so much stuff doesn't work, you may easily have a ground wire off at the battery.

When doing this type troubleshooting, If the appliance is good (ie not open, meaning you would need to turn the switch on which will provide positive to the appliance) you will have voltage measured anywhere on the wiring, either side of the appliance. All it will tell you is that you have a circuit.