Archive for the ‘Testing’ Category

Marine electrical questions?

June 28th, 2010 by Kevin Hannula

Marine Ac/Dc attempts to answer your questions about boat wiring and marine electrical techniques, concepts, and products. We get lots of mail from folks in mid-project or who are just curious about their boat’s electrical setup.

There are loads of post already on the site which we hope you will browse through. If you’re trying to track down info about a more specific category, please use the search box in the upper right of this page or check out the list of various subjects farther down on this page.

If you aren’t able to find the info that you need to complete your particular boat wiring project, please send us an email at boatwiring@gmail.com.

Thank you for visiting. We look forward to hearing from you and hope that you will be able to come back often.

Posted in Battery Charger, Battery Switch, Boat Wiring, Bow Thruster, Circuit Protection, Corrosion, Cruisers, Gauge Panels, Harnesses, Marine Electrical, Navigation Lights, Pontoons, Runabouts, Signaling Devices, Switch Panels, Testing, Trolling Motors, Uncategorized, VSR, Wipers | Comments Off

O’Day Dilemma

November 14th, 2011 by Marine Ac/Dc

Hello Kevin,

My boat wiring question is:

I have a 1979 37′ O’Day sailboat, with an Aft Cabin with the original 4 breaker terminal mounted on the locker.

When I bought the boat in 2000, I replaced the existing Loran with radar and wired it into the panel where the Loran had been and added a VHF radio to the back of the panel. Both have individual fuse protection. O'day Sailboat

Everything has worked fine until a few weeks ago when I noticed I have no power to the panel – cabin lights, engine room light, radar, radio, and autopilot do not work.

Both the positive and negative lines from the main power source in the forward part of the boat were tested by me and tested good.

I was told that it could be a ground problem. I looked at the negative marine electrical bus bar inside the locker and what is there are the negative wires from the accessories and the negative wire from the main bank in the forward part of the boat. There was also another 10 gauge wire but not attached to anything.

Should there be a ground wire attached to the buss bar to the engine and could this wire be my problem in that it somehow become disconnected?

I installed a new six breaker panel replacing the original; I installed a new 30 amp terminal (6 terminals) inside the locker and ran each accessory positive to it and then from there to the panel; Each accessory negative goes directly to the to the bus bar along with the 10 gauge negative wire from the main power source. The new panel has a negative bar which I also attached to the bus bar.

I then turned on each switch and they all light up meaning power is there. But when I turn on any of the accessories at the actual device they do not work and all the panel lights go off. When I turn off the individual accessory the panel lights will go back on. This happens with each item- cabin lights, engine room light, radio, radar, auto pilot.

Can you help me?

Confused

Jordan

Hi Jordan,

The problem is either in the feed wire or the ground wire.

The best way to find your problem is to test voltage levels when the system is under a load.

The panel indicator lights will initially turn on because the low current draw of the lights induces a small voltage drop in the wire. When you turn on a higher draw device, the voltage drop increases and the light turns off.

You will probably find a bad cable connection or hidden splice.

Hope this helps,

Kevin

Thank you for your response.

While waiting to hear back from you, I continued to investigate the problem.

Although I found numerous other problems as the O’Day has the original wiring, the cause for the failure was due to corrosion inside the positive wire where it entered into the front panel for power. As I tried to pull the wire to locate it, it broke off and was corroded inside the insulation. The joys of an old boat.

I have rewired the entire aft by replacing all the wires and panel and everything is back in order.

Regards,

Jordan

Posted in Anchor Lights, Battery cables, Boat Batteries, Boat Wiring, Circuit Protection, Corrosion, Cruisers, Galley, Gauge Panels, Ground Issues, Harnesses-Dash, Harnesses-DC, Marine Electrical, Masthead Lights, Sailboats, Switch Panels, Testing, Voltmeter | Comments Off

Plane Pain

September 13th, 2011 by Marine Ac/Dc

Hi Kevin,

I have a 1991 Sea Ray 220DA with a 2006 Mercruiser 5 litre mpi.

Last time we were out on a trip, we were on plane and everything was fine. All of the sudden, we lost all power and the boat shut down.

After messing with the boat battery cables, the engine compartment blower came on, so I thought maybe it was just a loose connection.

I start the boat and go to get on plane and lose everything again, no power what so ever. Again I went through the wiring from the batteries to the battery switch and back to the starter and all seemed to be in good condition with good connections. So, after a while of just sitting there the blower comes back on and everything is back to normal.

Again, I start the boat and put it in gear and again it dies and we have no power. As you can imagine this was a very frustrating trip, this continued to happen the whole weekend and I never figured out the problem.

The last time it happened after messing with everything under the engine hatch with no luck I moved to messing with the boat wiring under the dash near the ignition switch just by giggling the wires blindly then all of the sudden we had power. I should mention that before just losing everything all of my gauges would bounce down to nothing then back to normal real quick and at the same time the engine would die for that second then back then do it for good.

So, obviously there is something loose and when we hit a wave or too much vibration we would lose the connection. After the trip, back at my house, I took the dash panel off and looked at everything but cannot figure out what the problem is.

Any thoughts on what I should look for? I don’t know what would cause total loss of power.

Hope you can help.

Thanks,

Dewayne

Hi Dewayne,

My best guess would be to look at the main boat harness plug on the engine. It is a black, molded plug that is about 1 1/2″ in diameter. It usually on the stbd side of the engine.

When you unplug it, the two big terminal pins are the main positive and negative that feed power to you helm and gauges. Intermittent connection of this positive pin would cause these problems. Engine temperature and vibration would amplify it.

Kevin

Kevin,

Thank you for your quick response.

I just checked the plug and you were right! I turned the battery switch on and the bilge blower, when I moved that plug the power cut, moved it again power came back.

There was a hose clamp helping to hold it in, so I loosened the clamp and pulled the plug. The pins looked ok so I plugged it back in and tightened the clamp. Seems to be ok, but was able to cut power by giggling it hard.

Hope this fixes my problem.

Thank you I appreciate your help,

Dewayne

Posted in Battery cables, Battery Switch, Blower, Boat Batteries, Boat Wiring, Cruisers, Ground Issues, Marine Electrical, Marine Engines, Testing | Comments Off

Turn it up. Radio.

June 27th, 2011 by Marine Ac/Dc

Kevin,

I have a 1995 Mercruiser 5.7L 350.

The boat wiring problem I’m having is that when I am running the boat and have the stereo on, it will cut out when my navigation lights, blower, or bilge pump are turned on. I had issues with the gauges reading erratically too.

So, I cleaned all battery terminals, cleaned the two main grounds into the block. I also ran a daisy chain ground from the gauges to the negative on the battery to bypass the existing ground just to check that ground.

Everything was running great, with the stereo blasting (stock marine unit, no amp), until I turned on any of the above mentioned accessories. Then the stereo cuts out, voltage drops on the gauge, and the other gauges act up a little.

I do not have a ground bus under the dash. All the wires seem to just disappear down each side of the boat.

I tested the alternator with a multimeter (read was 14.5). The stereo will come back on after the accessory remains on.

Any suggestions would be helpful. alpine stereo

Sheri

Hi Sheri,

You are dealing with a voltage drop issue. The more current that passes through a wire, the more voltage drop is induced. You don’t notice it when your navigation lights get slightly dimmer when your blower is turned on, but it is obvious when the stereo shuts down.

The solutions are to either increase the size of the wire that supplies power to the helm and its ground or run a separate power and ground for your stereo back to your battery or bus system. Please remember to install circuit protection at the battery end of the new power lead.

This will solve your problem,

Kevin

Posted in Bilge Pumps, Boat Batteries, Boat Wiring, Ground Issues, Marine Electrical, Navigation Lights, Pontoons, Runabouts, Signaling Devices, Testing, Voltmeter | Comments Off

Which Wire Where?

May 9th, 2011 by Kevin Hannula

Kevin,

I have a 2004 Trophy 2002 boat with dual batteries and a battery switch (off, 1, 2 both).Boat Wiring Store offers the internet's most complete line of battery cables.

I am confused with the boat wiring for the batteries.

  • The battery on the left facing the back of the boat has two wires. I assume red for positive and yellow is negative. I really can’t see where they are coming from.
  • The other battery  where the battery switch is located has a red wire coming from the battery switch which I assume is positive and a yellow coming from a grounding block (at least that what it looks like) which I assume is negative to the battery.

Then I have two more wires one black and one yellow. I assumed negative but not sure if I am correct and what they are for. Do you have any explanation if I connected these wires correctly or what those two extra wires are for?

Thanks,

Frank

Hi Frank,

Before making any assumptions on which wires connect to which posts on your battery, I strongly recommend tracing them to their origin.

In general, Red is battery positive and Black or Yellow is battery negative.

If you trace the red wires to a battery switch or distribution panel, you can assume these are the positive leads.

If you trace the yellow and black to a ground bus or engine negative terminal, you can assume these are the negative leads.

Hope this helps,

Kevin

Posted in Battery Charger, Battery Switch, Boat Batteries, Boat Wiring, Circuit Protection, Galvanic Corrosion, Ground Issues, Marine Electrical, Pontoons, Runabouts, Testing, Voltmeter | Comments Off

Hull Ground?

February 28th, 2011 by Kevin Hannula

Hi Kevin,

My aluminum boat wiring has the negative returns and negative side of the battery all tied to the hull.

I would like to isolate the negative return and run all negative returns to the battery with the hull isolated.

My question is: What do I ground the aluminum fuel tank to? It is connected to the hull.

Thanks,

Scott

Hi Scott,

Grounding to an aluminum hull is un-avoidable. Some components just end up being connected. You are actually at risk of even greater galvanic corrosion if the hull is not tied to the negative side of your system.

I would recommending running grounds for all components and not using the hull as a conductor. To comply with the USCG requirements, the metal components on your fuel tank (the tank itself) need to be connected to the boat’s DC negative ground also.

Hope this helps,

Kevin

Posted in Boat Wiring, Circuit Protection, Corrosion, Cruisers, Galvanic Corrosion, Marine Electrical, Navigation Lights, Pontoons, Runabouts, Signaling Devices, Switch Panels, Testing | Comments Off

Galvanic Isolator Boat Wiring

October 25th, 2010 by Kevin Hannula

Hello Kevin

I just purchased an “Easy Add AC” marine shore power kit.

A friend says that I should also have a galvanic isolator in my marine electrical system.

It looks like I should place the isolator in line with the ground in between the new system’s shore power inlet and the 120v panel. What is the best method of accessing the ground wire for this purpose? I assume the green ground wire coming off the 120v panel goes to the DC ground buss despite using the isolator?

Please advise.

Thanks,

Chip

Hi Chip,

Your galvanic isolator needs to go in the green grounding wire between the AC inlet and the AC panel. You will need to cut back the white insulation on the 10/3 boat cable to access the green wire. The easiest place to add the GI to your boat wiring will be next to your new shore power inlet. Remove the cover on the back of the inlet to access the green wire.

The green wire that comes off of the back of the AC panel goes to the DC ground bus.This provides a low resistance path to ground (required by USCG) in case of a major AC fault.

Please let me know if you have any other questions.

Thank you for your order,

Kevin

Posted in AC Wiring, Boat Wiring, Circuit Protection, Corrosion, Cruisers, Marine Electrical, Shore Power, Testing | Comments Off

Maxed Out

August 30th, 2010 by Kevin Hannula

Kevin,

I recently bought a used boat. It was improperly grounded and burned some of the boat wiring out. My mechanic repaired several problems, but one problem still remains.

When you switch on the ignition most gauges jump to their maximum. For example the trim is maxed out to the right no matter at what level the outboard really is. The oil pressure gauge does nothing. The tachometer goes clear to the right. The speedometer goes to about 10 miles an hour and stays no matter what speed the boat is moving.

Other electric things work correctly, such as the horn, the starter motor, the trim mechanism, bilge pump, bilge blower, and so forth. The stereo system, the marine radio, and GPS seem to be non-functional.

What is that it that can cause all gauges to fail like this? By the way, the boat is a 2002 Chaparral 180SE with a Mercruiser 3XL engine and outdrive. The boat has been badly mistreated, and has required a lot of work to get it functioning again.

Thanks for any suggestions you can give.

Steve

Hi Steve,

It sounds like you have a combination of marine electrical problems.

My guess is that you have more burned out wires.

You should start by checking for 12 volts at each gauge. + on purple and – on black

Then, using an ohm meter check the following

  • Trim position – brown/white – 60 ohms down 11 ohms up
  • Oil pressure – lt blue – over 240 ohms 0 psi 33 ohms 80 psi
  • Fuel – pink – over 240 ohms empty 33 ohms full
  • Tach – gray – test for continuity through harness to engine

As for the speedo, check for a plugged or melted pitot hose, if so, replace the hose. You should also clean up the pickup and check for a bent axle on paddle wheel

Hope this helps,

Kevin

Posted in Boat Wiring, Cruisers, Gauge Panels, Horn, Ignition Switch, Marine Electrical, Navigation Lights, Runabouts, Signaling Devices, Switch Panels, Testing, Trim | Comments Off

Test before replacing charger

August 23rd, 2010 by Kevin Hannula

Kevin,

My boat wiring includes a Guest 2623 marine battery charger, it is about seven years old and the middle lights for the charger no longer come on.

Does this indicate that the charger circuit is bad and a new one is in order?

Thanks,
Dana

Hi Dana,

I asked a friend of mine at Guest Marine Electrical about your situation. He wrote that, “…this may be just be the LED is going out and the charger is still good. You could check the output of the leads to be sure. The charger will go through its algorithm as long as it has output.”

In other words, you will want to test the output voltage with a digital volt meter to see if the charge may still be performing even though the lights are not on.

Hope this helps,

Kevin

Posted in Battery Charger, Boat Wiring, Marine Electrical, Pontoons, Runabouts, Shore Power, Testing, Voltmeter | Comments Off

Boat wiring a chart plotter

August 2nd, 2010 by Kevin Hannula

Kevin,

Just came across your web page and it seems great. I couldn’t find an answer to my question, so here it is.

I have a 1992 Sea Ray 330 Sundancer. It has two 7.4Ltr engines and 3 batteries. I want to replace the stereo and add a chart plotter.

My question is where do you run the boat wiring? I assume you don’t just splice it to another wire. How do you know which battery you’re wiring it to? Is there a buss somewhere that you tie in accessories?Sea Ray - Where Land Ends, Life Begins

Thanks for any info,

John

Hi John,

Your marine electrical setup has one battery for each engine and one for the house systems – your stereo and chart plotter should be connected to the house battery.

If you are replacing the existing stereo, I would use the existing power wires. These probably run from the stereo to a main DC distribution panel in the cabin or to a breaker panel in the helm. Stereo power boat wiring has not changed color for years. You should have:

  • Yellow (constant power)
  • Red (switched power)
  • Black for ground.

The speaker wires are:

  • White-white/black,
  • Green-green/black,
  • Gray-gray/black
  • Purple-purple/black.
  • You may also have a blue wire from the stereo that is the remote turn on for an amplifier.

Finding power for the chart plotter may not be as easy. In your helm, there should be a ground buss for the negative wire. You will need to do some exploring to locate an adequate power supply. I would look on your helm breaker panel for an electronics or helm accessory breaker. If one is open, use it. Confirm that the breaker rating is the same as the rating required by your chart plotter manufacturer. If too large, install in in-line fuse at the correct rating.

If a helm breaker is not available, your two options are to piggy back your power from another helm accessory or run a new wire to the battery or distribution are. Either way, install an in-line fuse as close as possible to the power source to protect the wire and your new electronics.

My preference is to piggy back your power from one of the helm breakers. Most plotters do not draw an excessive amount of current and it is much handier to have all of your circuit protection in one location.

Please let me know if you have any questions,

Kevin

Posted in Boat Wiring, Cruisers, Marine Electrical, Pontoons, Runabouts, Testing | Comments Off
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