Lingering Light

Boat Wiring Guys,

I put in new VHF radio into my sailboat. The installation seemed to be successful except...

Now when I turn off the marine electrical panel switch for the VHF, the green light from the breaker goes out but not right away, slowly turning off in about half a second.

Is there any problem with this? Did I screw something up?



It is not a problem.

The light in the switch gets power when the output side of the switch has power. The residual light is caused by a capacitive charge that is in the VHF radio. This capacitor in the radio helps with noise and voltage spikes but will give the appearance of voltage on the power wire which makes the light stay on.

Hope this helps

Dance Dance Devolution

Hey Kevin,

I know you’re a marine electrical engineer, but I have a marine audio question and I’m not sure who to ask. If this is not your thing, I completely understand. If you have time, and you can answer my question, I would really appreciate it.
I have an old 1976 double decker party barge with the following audio system:

  • Rockford Fosgate RFX9700CD head unit (40w x 4 peak, 17w x 4 RMS) mounted in the driver’s console
  • Four Poly Planar MA 9060W box speakers (rated for 100w max, 60w RMS) mounted on underside of upper deck
  • Premium 16 gauge marine-grade speaker wire
  • All new tinned marine wiring throughout the whole boat (much of which came from your retail site)
  • One Pyle PLMRBS8 powered subwoofer mounted under a seat

I completely restored this boat in the spring of 2010, and I installed all this stuff new out of the box at that time.

The problem I’m having is that the radio is cutting out a lot if the volume is turned up as loud as you would want it when people are dancing and having a good time. At normal volume levels, everything is fine, but as soon as we turn it up for a good dance song, it starts cutting out. Here’s the four possible reasons I thought of:

  1. Do I need more power for those 4 speakers? Could that be the problem?
  2. Could the head unit be getting too hot? There’s not really any ventilation in that center console, although the center console is usually mostly shaded from the sun by the upper deck.
  3. Could the fuses on the back of the head unit be going bad, or something like that?
  4. I thought maybe it could be a short in the ipod adapter wire, because when you more the wire around sometimes it seems to get a little better, so I ordered a new one of those today, just in case that’s the problem.

If you have a minute and can answer my question, I really would appreciate it. Thanks for all your help in the past.


Hi Paul,

The current draw of the radio is more than your marine electrical can handle; the louder the volume, the higher the draw, the more the voltage drops. When the voltage gets too low, the stereo shuts off. When the stereo shuts off, the voltage goes back up, and the stereo turns back on.


Run a separate, 12 awg power wire and ground for the stereo back to the battery (or boat battery switch and ground bus) with an in-line fuse at the + battery connection.

This will solve your problem.



Thank you very much. I hadn’t thought of this. If I may, I’d like to ask another question to be sure I know how to fix it the way you suggested.

The wiring that’s in place for the stereo is using the complete pontoon boat wiring harness from EzAcDc, running through one of your switch panels on the driver’s console, and then to your smart battery switch (2 battery system). All the grounds go to a ground bus. The wiring harness has an in-line fuse on it, but I think that’s for the whole harness, not specifically for the stereo.

Are you thinking that the power wire for the stereo (in the pontoon wiring harness) is too small? So I should just swap the power and ground wires for the stereo to larger wires, running the ground wire to the ground bus, and running the new power wire through the switch panel, then to a in-line fuse, and from there directly to the secondary battery’s positive terminal? This will bypass the smart battery charging system, but that’s fine with me if it will fix my problem.

Would anything change about your recommendations if I decide to put a 50×4 marine amplifier on the 4 speakers? I believe you are 100% correct about what my problem is; however, I also believe that the 4 Poly Planar speakers would sound better with additional power. Like I said, they are rated for 60 watts RMS, and they are only getting 17 watts RMS from the head unit.

Thanks again. You’re awesome.


Hi Paul,

Isolating the power and ground for the stereo will solve your problem. The 16AWG is adequate for a smaller stereo, but once you go larger, it is not enough.

I would run the power back to the battery switch and connect it to the same switch stud as your boat accessory harness. The 4′ of 2 AWG red from the switch to the battery will not effect the voltage drop. The ground can run back to the ground bus for the smart switch system.



Boat Wiring Wizard?


I could really use some of your wiring wizardry.

I have have a 2009 Centurion Avalanche. I put it up for winter and everything was working fine. I charged and installed the boat batteries after winter. All of the switches work, horn, stereo, pump, etc. I go to bump the key and I get nothing. The boat is still on the trailer and before I drag it to the lake I wanted to ensure that power was getting to the starter.

I made sure that the batteries are fully charged, boat battery switch is in the on position, emergency kill switch is in place, boat is in neutral…and I get nothing when I bump the key. I pulled the fuse behind the ignition switch and it looked fine.

The boat has dual batteries. The boat dealer added an marine battery switch last year as the batteries were draining even though the battery switch was turned to the off position.

The boat on has forty hours on it. After working in a confined space and pulling my hair out, I could use some expert advice.



Hi Tommy,

If the instruments have power when you turn on the key, then I would check the neutral safety switch. Based on Standard Boat Wiring Colors, follow the yellow/red wire from the starter post on the key switch to the neutral safety switch in the shifter control.

If the key switch has no power, I would check the breaker on the engine that feeds power to the ignition.

If you use a voltmeter or a test light, you will be able to find the problem. It may be something as simple as wiggle the shifter a little or replacing the starter solenoid.

Hope this helps,



I’m in the boat now with even less hair.

The ignition in the on position does nothing as well as the start position.

It appears that power isn’t getting to the switch. The fuse leading up to the switch looks good. I have also been playing with the shift lever to find the sweet spot, no luck.

Trying to locate the breaker on the engine.

Thanks for all of your advice, hopefully I can get on the lake today.



You the man!!! It was the engine breaker.


Shocking Shifter


I have a 1987 Sea Ray Sorrento S-19 with a 4.3 Liter OMC Stern Drive – with less than 400 hours on the motor.

I just put the boat in the water this weekend – and experienced a slight electrical shock when touching the shifter handle after starting the engine. Given that they are slight shocks I am thinking it may be the ignition switch.

I’ve looked at the boat’s wiring as much as I could see and didn’t see anything that would suggest a short. It all looked in good shape. I also reconnected the boat battery wiring and that didn’t work. 

Fuses? Ignition switch? Any thoughts?!

Thank you!


Hi Larry,

It is probably not your boat’s ignition switch.

The starter circuit goes through the shifter, but not the ignition. Since your problem is still occurring after the engine has started, I would look at connections on the engine.

Your boat motor has a shift interrupter circuit that basically connects your ignition coil to the shift cable. When operating properly, the shift interrupter will momentarily ground the coil during shifting. When not functioning properly, crazy things happen.

The shift interrupter should be on the starboard side of the engine and will have a shift cable connected to it. Chase the wiring from the negative side of the ignition coil to the interrupter to find your problem.

Good luck,


Four Winns Wiring

Hello Kevin,

I have a 1989 Four Winns Liberator 201 with a 350 OMC motor. I know that it’s early, but I pulled off the boat covers today because I wanted to check everything before I put her back in the water.

When I went to hit the boat horn to test it, the horn sounded weak and eventually faded and did not work.

Next the navigation lights would not turn on. But when I hit the horn, the lights will turn on until the horn is released then they go off. Not sure if it could be a bad ground or short in the wiring.

I removed the access cover and found someone has cut and spliced wires on the boat before. There are also some wires disconnected and zip tied up and others just cut.

The boat blower motor did work when starting the boat but now it also will not turn on. I’m not an expert in marine electrical by any means but would like to find the issue my self. I have a voltmeter but never used it other than checking glow plug relays on diesel engines. I have used a test light on trailers – checking for power and such so I do have a little knowledge but not where to start on this project.

Any help would be great.



Hi Mark,

I’m a HUGE Liberator fan. I worked at Four Winns during the era after their production.

There are few marine wiring items to check since several things have quit working.

  • Main engine plug – round plug 1 1/4″ diameter on the starboard side of the engine. Unplug and check terminals
  • Boat harness ground – check ground connection on rear bell housing of the engine
  • Helm fuse block – check ground and power leads on the main fuse block under the helm

Once your find the corroded connection, replace as necessary.

Good luck,