Boat

Have Boat Questions? Ask a Boat Repair Expert.

Ask an Expert,
Get an Answer ASAP!

I've traced a ground fault to within my Yamaha 150 outboard.

Customer Question
But I can't figure out...
I've traced a ground fault to within my Yamaha 150 outboard. But I can't figure out where the current crossover is occurring. If I disconnect the main black electrical harness in the engine, the fault remains. If I disconnect the hot wires at the solenoid, it disappears. The smaller of the two red wires connected to the solenoid creates a full 12V ground fault, but I can't trace where that red wire goes. Nothing visually obvious wrong.
Submitted: 3 years ago.Category: Boat
Show More
Show Less
Ask Your Own Boat Question
Answered in 1 minute by:
6/8/2015
Marine Mechanic: Jason, Marine Mechanic replied 3 years ago
Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 18,240
Experience: Degree in Marine Technology. Gas and diesel marine mechanic.
Verified
Hello my name is ***** ***** am I speaking with?
I don't quite understand what it is you are doing. What problem is the engine having that you are trying to correct?
Ask Your Own Boat Question
Customer reply replied 3 years ago
My name is Tom. Do you know what a ground fault is? I'm loosing current, through some unintended circuit. I've disconnected all the fuses to things like lights, horn, wash down pumps, bait aerator pump, radio, etc. So, none of the red (positive circuits) should be drawing current. When I attach a volt meter from the positive lead of the battery, to the (disconnected) positive wire that runs to the engine, I read 12 volts. It should read zero if nothing is drawing current, or completing the circuit (like I said, I've disconnected all other circuits).
Customer reply replied 3 years ago
Should I expect a reply, or are you done with this question?
Customer reply replied 3 years ago
(Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Marine Mechanic: Jason, Marine Mechanic replied 3 years ago
I don't quite understand, is the battery running dead on you when the engine sits, is that what is going on?
Ask Your Own Boat Question
Customer reply replied 3 years ago
I haven't noticed it running down when it sits, but I always turn off my battery selector switch. When running the boat is running at idle speeds, I notice that the voltage being received at my chart plotter fluctuates between 10-11 volts, which sometimes causes it to shut off. And the horn won't work. If I rev the engine, the voltage will rise to 13, and the horn works. After a day on the water, the battery is run down. Using my voltmeter, I tested for a ground fault, and see that I have one. And that takes me back to my previous statement, of having disconnected all the power drawing circuits (including the bilge pump), and still see current flowing across the positive lead.
Marine Mechanic: Jason, Marine Mechanic replied 3 years ago
What does the voltage read at the battery terminals with the engine running in the 1500-2k rpm range?
Ask Your Own Boat Question
Customer reply replied 3 years ago
Around 13.
Marine Mechanic: Jason, Marine Mechanic replied 3 years ago
Okay that's to low, you should be between 14.1 and 14.9, at 13 it's not really charging. Have you located the 50 amp fuse on the engine, an if so, is that fuse good?
Ask Your Own Boat Question
Customer reply replied 3 years ago
It is charging, perhaps a bit low. I'm reading the current coming out of the battery (not going in), so I wouldn't expect it to be much higher than 12-13.
Yes, the 50 amp fuse is ok. I notice that if I pulled that fuse, the ground fault disappears. I assume that fuse is between the alternator and the battery.Do you understand what I mean when I say a "ground fault". It's not a "short circuit", but rather a "minor" leakage of current from a positive wire to another ground somewhere.
Marine Mechanic: Jason, Marine Mechanic replied 3 years ago
Do you understand what I mean when I say a "ground fault". It's not a "short circuit", but rather a "minor" leakage of current from a positive wire to another ground somewhere.
I don't think you understand what a ground fault is. This is all DC electricity you are working this, there is no such thing a ground fault in DC. In AC, where you have 3 wires, a Hot a neutral and a ground. A technical "short circuit" is when hot touches neutral. And a technical "ground fault" is when hot touches ground.
Since this is DC electricity lets try not to use the word ground fault. It is improper. With DC circuits there are only 3 possibilities. An open circuit, a short circuit, and a functioning circuit. And that's it.
The problem you are having is your charge voltage is to low. It needs to be 14 or better. Run the engine again, ground the meter negative lead to battery negative, and then check voltage at the 50 amp fuse. does voltage come up?
Ask Your Own Boat Question
Customer reply replied 3 years ago
My chartplotter shows that it is only getting 10 volts from a fully charged battery. A short circuit would blow a fuse, an open circuit wouldn't allow it to turn on. Somewhere I'm loosing current (hence the term ground fault). I'm not making up the terminology. It's widely used in boating. It describes what I'm witnessing immediately (i.e., not after a period of time when a fully charged battery runs down). Thanks for the attempt to help, but I think its best to end this Q&A.
Marine Mechanic: Jason, Marine Mechanic replied 3 years ago
Your thinking of "Voltage Drop"....... Not ground fault. And really you are confusing yourself here because you don't understand what the words mean.
I will opt out.
Ask Your Own Boat Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a marine mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Dominick Your Own Question
Dominick
Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1,009
1,009 Satisfied Customers
Experience: 25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified

Dominick is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Dominick

Dominick

Marine Mechanic

1,009 satisfied customers

25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified

Ted G.

Ted G.

Rigger, Diagnostician

704 satisfied customers

40 years boating, Safe boating instruct., Offshore Race promoter, Failure Analysis, Expert Witness

John White

John White

Marine Mechanic

306 satisfied customers

11 years experience working on outboards, inboards, sterndrives & pwcs

Jason

Jason

Marine Mechanic

18,240 satisfied customers

Degree in Marine Technology. Gas and diesel marine mechanic.

Tan

Tan

MerCruiser Certified Technician

11,264 satisfied customers

40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.

Jeff G.

Jeff G.

Marine Mechanic

4,729 satisfied customers

42 years experience, Certified Master Technician, All Major Outboards, Sterndrives, Hi-Performance

Captain Dave

Captain Dave

Marine Mechanic

2,672 satisfied customers

USCG Licensed Captain, 20+ Years Boating, Fishing, Maintenance and Repair Experience

< Previous | Next >

Related Boat Questions
1982 50 hp J50BELCNR Outboard Motor Working on my outboard
1982 Johnson 50 hp J50BELCNR Outboard MotorWorking on my outboard motor. I am changing out the water pump on it and i had to remove the starter to get to the gear shaft. I put the starter back on and … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I have a problem with my oil transfer from the auxiliary oil
I have a problem with my oil transfer from the auxiliary oil tank to the main oil tank on the engine of my yamaha 150(2003) I have changed the oil sensor and put a new oil transfer pump in the auxilia… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
I have a 2006 115HP 4 stroke mercury outboard. The battery
I have a 2006 115HP 4 stroke mercury outboard. The battery runs down quickly. With the key off there is an electrical draw. I have taken various wires off to isolate the issue and I traced it to the s… read more
Jason
Jason
Marine Mechanic
18,240 satisfied customers
Need to make sure I have wires properly connected to solenoid
Need to make sure I have wires properly connected to solenoid and starter on 150 Johnson fast strike outboard… read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
11,264 satisfied customers
My 2002 Yamaha 8hp outboard has a motorized tilt. Although
My 2002 Yamaha 8hp outboard has a motorized tilt. Although my battery power is full up, when the tilt control switch is used, all that happens is quiet clicks. What is it?… read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
1988 Yamaha 150 V6 End of season last year I raised the
1988 Yamaha 150 V6 End of season last year I raised the engine to full position after running all gas out of engine. Removed both batteries and kept on charge all winter. Just put batteries in yesterd… read more
Jason
Jason
Marine Mechanic
18,240 satisfied customers
I have a 2010 Yamaha 150 hp - The outboard would not start
I have a 2010 Yamaha 150 hp - The outboard would not start .. seemed like a battery problem. I installed new batteries same problem - small click not turning the starter. Took the cowling off - checke… read more
Jeremy R
Jeremy R
1,069 satisfied customers
I have a M40d Tohatsu outboard motor with forward steering
I have a M40d Tohatsu outboard motor with forward steering and controls, it also has numbers 3c8 and a possible serial # XXXXX motor will not start, trim and tilt will not work, battery is good, conne… read more
Jason
Jason
Marine Mechanic
18,240 satisfied customers
Yamaha f50 now electrical power when key turned, power trim
Yamaha f50 now electrical power when key turned, power trim works ok checked fuse on motor? Can anyone help… read more
Jason
Jason
Marine Mechanic
18,240 satisfied customers
Jeff I have another problem for you. Got a 5.7lt 350CID engine
Jeff I have another problem for you. Got a 5.7lt 350CID engine wont wind over on starter and fuel pump wont energise. Have traced yellow/red trace wire too J1 multi plug on ECU and on crank this liven… read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
11,264 satisfied customers
I haye a 96 sea-doo xp [787 type engine] which attempts to
I haye a '96 sea-doo xp [787 type engine] which attempts to start as soon as the battery is connected. The small wire on the starter solenoid is constantly hot.I've traced the wire back to the 'conven… read more
James
James
Certified Marine Mechanic
Vocational, Technical or Trade Scho
4,094 satisfied customers
I have an issue w/ the ignition switch on a Johnson 35HP 1979
I have an issue w/ the ignition switch on a Johnson 35HP 1979 outboard, 35EL79A. There are six terminals on the back of the switch, and only five wires leading to it. I've figured out the battery (red… read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
11,264 satisfied customers
I need a wiring diagram for a 2000 johnson ocean pro 150 hp
I need a wiring diagram for a 2000 johnson ocean pro 150 hp starter. Starter gear won't pop up after I replaced old starter. I believe I have wires in the wrong place.… read more
Jeff G.
Jeff G.
Marine Mechanic
Vocational, Technical or Trade Scho
4,729 satisfied customers
i have a 90hp yamaha outboard motor with a yamaha 703 control.
i have a 90hp yamaha outboard motor with a yamaha 703 control. there are 5 ea. wires that go to the gauges .(red,black,yellow ,green,blue) can some one tell me exactly were they go.… read more
Jeremy R
Jeremy R
1,069 satisfied customers
Hi, I have an evinrude 2006 model 150 Hp ficht outboard.
Hi, I have an evinrude 2006 model 150 Hp ficht outboard. My problem is that the main electrical supply (for start, system check, tilt etc) is working Ok, but none of the utility equipment (fuel tank, … read more
Master Tech
Master Tech
Service Manager/Technician
Vocational, Technical or Trade Scho
1,167 satisfied customers
90 hp two cycle with no spark. Have checked the internal fuse
90 hp two cycle with no spark. Have checked the internal fuse which is good. where should I look next?… read more
Abiorca
Abiorca
Proprietor
Vocational, Technical or Trade Scho
1,768 satisfied customers
I have a Yamaha 40hp outboard motor that has been running fine.
I have a Yamaha 40hp outboard motor that has been running fine. Now it will not start or turnover. I changed the battery and it is still dead. I pulled the cowling and found a spare fuse but cannot fi… read more
Larry B.
Larry B.
Marine Service Tech
High School or GED
574 satisfied customers
i need to know how to hook up a Yamaha 115 outboard i need
i need to know how to hook up a Yamaha 115 outboard i need to know what wires go pos and neg on battery… read more
Larry B.
Larry B.
Marine Service Tech
High School or GED
574 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x