Kevin,
I am rewiring my outboard engine. I have already purchased 2 gauge rust-resistant tinned wire. Then I checked the existing boat wiring and figured out it that it is 4 gauge.
Is there a problem with over gauging a marine electrical system?
Thank you
Chuck
Hi Chuck,
There is no problem with over gauging, but under gauging will cause an increased voltage drop and may cause your engine to not start.
Thanks,
Kevin
Kevin,
The main DC voltage of my pontoon boat’s marine electrical drops when my running lights, electronics, and radio are on.
- The drop is around 6 to 10 volts.
- The main DC power on my boat wiring is 4 gauge and the run is about 12 ft.
- I’ve got two 8d batteries on a duel switch. I only use these batteries for accessories only, not for starting that boat engine.
Do you have any suggestions? The batteries are fairly new this past season. Before any draw the battry voltage is 12.6 volts
Thank you!
Barry
Hi Barry,
Check all of your connections – especially where the boat battery cables connect to the terminals.
A bad crimp will cause a high resistance point that will give a higher voltage reading with low draw, but a low voltage reading with a high draw.
Let me know what you find,
Kevin
Hi Kevin,
Two questions…
- Solder or crimp terminals?
- How do I select proper wire sizes?
Oh wait, make that three. Fuses or circuit breakers?
I have a Hurricane pontoon boat that’s starting to cause me some problems and I’m going to redo all of the boat wiring.
Thanks,
Barry
Hi Bill,
Hope this helps,
Kevin
Kevin,
I just upgraded my pontoon boat with a new stereo 50 watt x 4 connected and matching speakers.
When the volume gets to 22 or higher the stereo kicks on and off. When below that it plays fine.
What is wrong?
Thanks, Mike
Hi Mike,
The power feed/ground wire is too small.
As you increase the volume, the current increases. As the current increase, there is more voltage drop in the wire. When the voltage gets too low, the stereo shuts off.
If the stereo is connected into your existing boat wiring, either increase the main power feed/ground for the fuse panel or run a separate new wire for the stereo.
This will solve you problem,
Kevin
Hi Kevin:
I’m stuck troubleshooting the DC outlets on a recently acquired pontoon boat, and I’m hoping you can help. Here’s what’s going on:
- With one exception, none of the appliances I’ve tried (GPS, USB/DC adapter, AC converter from Radio Shack, etc.) work; that is, they behave as if they are not plugged in. The one exception is the USB adapter; it works very intermittently, I’d say once in 50 attempts.
- Two DC outlets are wired into the same switch on the panel. Neither one functions.
- Using a voltmeter, I tested the voltage of both outlets, and they both match the voltage on the battery meter, so the circuit seems okay.
- I tried installing new outlets; no effect.
- I’ve tested two of the appliances in my car to test the appliances themselves are working, and they are.
With very little boat wiring experience, I’m now stuck as to what could be the problem, or what else I might test. Any thoughts?
Many thanks,
Tim
Hi Tim,
The best way to find your boat wiring problem is to have your voltmeter connected to the receptacle and then plug in a device.
If the voltage starts normal and then drops when you plug in your device, there is a bad connection/corroded wire in the system. Search connections until you eliminate the drop. The voltage drop across the bad connection (high resistance point) increases with current. Since the meter draws very little, the drop is not noticed on the meter. AS soon as you increase the draw, the drop increases, and your device will not turn on.
Hope this helps,
Kevin
Kevin,
We have a 16′ pontoon boat with a Ray450 electric motor (6 battery) plus a trolling motor with separate battery charger.
About a week ago I noticed that the live well pump was working at a slow rate and then the radio started to cycle on and off. I
checked the, boat wiring, the batteries and motor – everything seemed fine. But, now nothing works off the auxiliary panel including the navigation lights, horn, livewell pump or radio. I can’t find any blown fuses.
Any ideas?
Thanks
MJ
Hi MJ,
A slow livewell pump and a cycling radio is a sign of low voltage. I would check the battery bank that your accessory panel is connected to and ensure it is charged properly and that all connections are good.
On multi-battery electric motor systems, sometimes a middle battery can be bad and cause 12 volt items connected to it to slow/shut down. If the other batteries are still charged, the complete marine electrical system will still have a high enough voltage to keep the electric motors running.
Kevin
Hi Kevin,
Have a 2005 Manitou 18′ Oasis and this year have had trouble with the pontoon boat wiring. Specifically, the battery runs down if it isn’t used for a while.
I checked current leakage and found on both the black and red leads a momentary drain of .5 amp which drops to 10Ma – almost like a capacitor charging, then stays at 10Ma.
Any Ideas?
Thanks
Bill
Hi Bill,
The usual suspect is the stereo. Most marine electrical radios are actually designed for automotive use and do not completely power down when you turn them off.
To make matters worse, as your battery gets older, it is effected more by a slow drain. Also, loose battery cable connections can cause the battery to not charge completely while the engine is running.
Try removing the fuse from the stereo and see if your slow drain goes away. If it does, consider adding a battery switch to your boat wiring. It will completely disconnect the battery while you are away. Our partners at EzAcDc have several battery switch systems that would work for you.
Kevin
Kevin,
I have a 1998 Manitou that I just put a new stereo and speakers in. It sounds great!
I wired it just like the stereo that it replaced it with. It has a red wire, a yellow wire and another positive called “Illumination wire” that are all three hooked up to power. One is direct and the other two are through the switch.
Anytime the boat is running and I have the stereo on, it shuts off anytime I push any button that uses electricity. If you hit the trim switch, the stereo shuts off. If you turn on the accessory switch, it turns the stereo off.
The weird thing is if you touch the trim switch, sometimes the stereo will turn back on by itself in about 20 seconds. Sometimes it won’t. The blower and the horn are the only two switches that won’t make the stereo turn off.
Any ideas?
Randy
Randy,
Your new stereo is more powerful than the old. It draws more current.
As you draw more current through a wire, more of the power is lost as the wire warms up. This power loss is observed by a lower voltage at the end of the wire.
The stereo may work fine when only the stereo is on, but as soon as you add the current of another device, the voltage drops too low and the stereo shuts off. Most other devices on you boat just operate slower or dimmer and you will not notice.
Solution:
Increase the size of the power feed and ground for your stereo. Make sure you have circuit protection on the power feed as close as possible to the battery.
Hope this helps,
Kevin
Kevin,
I recently installed two new halogen overhead lights on my boat. I tied them into the anchor light boat wiring on my T-top.
The original wire that fed the single anchor light is 10 gauge, so I figured it would be sufficient to handle all three boat lights combined.
The problem is that when I flip the switch for the new overhead lights they are slow to come on and are dim when they do come on. The anchor light seems to be fine.
Surely it’s not a low battery because I replaced it before starting my boat lighting project.
Could I have a loose connection somewhere or should I simply charge the battery?
PC
PC,
Your problem is voltage drop. Your boat has a 10awg wire feeding the anchor light to comply with the NMMA (National Marine Manufacturer’s Association) standard of no more that 3% voltage drop to the stern light.
Your new halogen overhead lights probably each have a 55 watt bulb. Combined, these lights draw 9.2 amps. Your voltage drop on your anchor light circuit when you add these lights is 12%. This would be noticeable on the halogen lights, but not on your anchor light.
Another possible problem is a loose connection. Poor connects cause resistance in the circuit. Voltage drop in your wire = resistance x current. As you increase your current (add more lights) and increase your resistance (poor connections), the voltage drop in the wire increases. If you are starting with 12 volts and you loose 5 volts in the wire due to voltage drop, then there is only 7 volts left for your light.
Hope this helps,
Kevin
