Trailering Magazine Archives - Trailering Maintenance
Troubleshooting 101 Electronics:
A BoatU.S. Marine Center expert offers some advice---before it's needed.
As every boat owner knows, or will soon learn, Murphy's Law loves being on the water. Ironically, it originated at Edwards Air Force base, far from any lake, river or bay. Captain Edward Murphy, an Air Force engineer, was trying to figure out why a test he was conducting had failed and discovered an electrician working on the project had improperly wired a transducer. Disgusted, Murphy uttered the words, "if there's a way to do it wrong, he will find it." In more modern times, Murphy's Law has changed to 'if something can go wrong, it will." When it happens on a boat, the day can go south real fast if there isn't a troubleshooter onboard.
Mike Campbell is an electronics expert at the BoatU.S. Marine Center in Newport, California. Every day he can be found talking with BoatU.S. Members and offering advice, which can be considered "trouble shooting" before something happens. He has received calls from Members in the Pacific Ocean asking how a VHF or a GPS can be brought back to life and talked them through a series of steps which, usually, result in the unit doing what it is supposed to do. Campbell is well aware of Murphy's Law. In fact, he makes a living because of it.
Troubleshooting a Fixed Mount VHF
The modern VHF radio that is attached to a shelf or on the console is good for up to ten years of substantial use-and even longer if it is taken care of. Mike Campbell says many problems appear shortly after a VHF is purchased because it is installed incorrectly. "The radio has to be mounted with room in back of it so that air can circulate," he points out, "and too many times I've had calls from boaters on their cell phones telling me the radio they just bought must be a lemon. That just isn't the case most of the time."
Instead, the VHF has been mounted too close to a wall and the resulting heat it generates isn't allowed to dissipate. This can lead to a complete shutdown of the unit and a possible end to its life. Campbell says it is a common installation problem when a VHF is placed inside a boat because space is always at a premium. Usually, he will tell a boater with a inoperative radio to shut it down and, if possible, set it on a table. And usually, the radio is up and running after being allowed to cool down.
"Another common problem with the fixed mount units is the radio lights up but doesn't do anything else," Campbell says. "This is when you have to check and see if there is 12 volts getting to the radio. Batteries will operate with 12.5 volts most of the time but if it has run down, then the problem isn't the radio but the fact the battery has to be recharged." But before you turn on the engine or plug in a charger, take a good look at the battery itself. If the contacts are corroded, (and you will see it on the posts) then the output is going to be less than it should be. A wire brush or even taking a knife and scraping the posts will provide a clean surface. The corrosive marine environment (and salt water is even worse) is always a suspect when a battery doesn't seem to be doing what it should be doing.
ransmissions but is unable to transmit. It takes more energy to send a message than it does to receive one. As a result, check the battery contacts again. If that appears to be in good condition, then its time to trace the coaxial cable in search of an open or broken section. This is where the continuity checker is used.
Troubleshooting a hand held VHF
The portable VHF radio uses either a Nicad battery (most common) or a lithium battery (newer and expensive). The first component to look at when a hand held VHF isn't working is the battery. "Whether it's a fixed mount or a handheld, the VHF radio problem is usually found in either the power supply or the antenna," Campbell observes, "and so the first thing you have to understand is how the battery that is being used operates."
Nicad batteries are rechargeable but this doesn't mean these power sources will last forever. Over time and through use, the battery begins to become less efficient and eventually has to be replaced. A common mistake that is made with charging is not allowing the battery to run down (most will operate until it has 5% of a charge remaining). Nicad batteries have a memory. This means if it isn't allowed to run down, the battery will actually become less able to hold a charge. An example is taking a fully charged battery out on the trailer boat, operating it for one hour, taking it home and plugging it again for another 12 hours. This isn't healthy and the battery will actually begin to decompose internally so that after a period of doing this, the battery will only have a life of twenty minutes or so. "The rule of thumb for this kind of battery is one hour of recharging for every hour of use. But use it for eight hours or so before charging it again, advises Campbell. "That will increase the life of the battery tremendously."
Another little known battery fact for hand held VHF radios is that many are designed with an ability accept AA batteries of needed. "They have either a separate tray or a holder and can be switched over to the kind of battery that is going to be used," Campbell notes. If you own a VHF, get the instructions out or contact the manufacturer in the event you can't locate the AA battery option. If this is difficult, a BoatU.S. Marine Center can assist if the radio was purchased from us. One caveat: if your radio operates on a lithium battery, the AA option won't work. Instead, there is usually a cigarette lighter adapter included with the purchase (if not, then it's available as an option).
If power isn't the problem, then the radio may have a bad antenna. You'll know this is the situation if you can only receive but can't transmit. If this is the case, the unit may not be repairable onboard. It may have to be sent to the manufacturer for a new antenna at which time, the cost to do so could possibly outweigh the price of a new model.
One other note about the antenna. VHF radios operate with line of sight. A 1-watt unit can reach one mile and the 5-watt unit (the most common) reaches five miles. It is important to understand since the earth's surface curves, and you are operating a VHF either in your hand or with a fixed mount unit that has an antenna a few feet above the surface of the water, the place you want to reach may not be "reachable." This is where sailboats have an advantage because many mount their VHF antenna on the top of their mast (of course it also means they have to climb the mast if there is an antenna problem).
Mike Campbell has had frantic cell phone calls about hand held VHF's that were inadvertently dropped overboard. "The news I have to give them usually isn't good," he says," and 90% of the time, the radio is toast." Still, in the event it happens to you, he suggests the following: open the radio, take out the batteries and allow to dry for 24 hours. Under no circumstances should you try to dry it out and operate after only a few minutes of coming out of the water.
Hand Held GPS Troubleshooting
The global positioning system (GPS) uses as few as 8 and as many as 10 of the 24 satellites currently in geosynchronous orbit (they move with the earth's rotation) 11,0000 miles above the earth. The older hand-held GPS units can operate for 8 hours on a set of batteries and the newer ones will last as long as 12 hours. The number one problem is the more the GPS is used to pull up way points and go to different locations and pages, the more power it is going to require and the faster the battery is going to weaken. As a result, always have a good supply of AAA batteries on board when the GPS is going to used for a long trip.
Campbell recalls a frantic phone call from a new user of a handheld GPS who was onboard his boat and concerned the unit wasn't completing its first step of acquiring satellites. When he asked the boater where he was sitting, there was a long pause. He was inside the cabin up near the V berth. Lesson Number One: GPS needs a clear view of the sky (for overhead positions) or a nearness to windows (for satellites located near the horizon) in order to operate. The patch antenna can't obtain the satellite signal through thick fiberglass or metal. It will acquire satellites through bimini tops.
If the GPS lands in the water and is quickly fished out, chances are good it is not going to be operable. Most GPS units are labeled as 'water resistant" but that doesn't mean they are "water proof." They'll operate fine in a rainstorm or with spray coming over the side but an extended soaking under water is probably going to mean the end. Still, Campbell says he's heard of units being opened up, the batteries taken out and silica gel placed inside to displace the water while drying for 24 hours before being turned back on and running with little problem. It's rare when it happens though.
The Biggest Problem
Being in the trouble shooting business, Mike Campbell has just about seen (and heard) it all. And through these experiences, he's learned some valid advice to avoid the need for trouble shooting: Getting electronic units wet should be avoided at all costs. Interestingly enough, the place where this occurs most often isn't out in the middle of the lake or river. It's at the dock where a boat owner decided to hose the boat down after a day on the water. That's when the fixed mount VHF gets soaked or the handheld GPS is left under a running hose for five minutes.
"The products that are available today are good quality," he says. "The problems associated with them can usually be fixed if the boat owner stays calm and thinks the problem through. If they can't, there is always a BoatU.S Marine Center that can lend a hand." Mike Campbell knows that all too well.
Campbell's Troubleshooting Tools to have Onboard
- A flat and a Phillips screwdriver
- Diagonal cutters
- Adjustable wrench (crescent works fine)
- A set of socket wrenches and drives
- Multi meter-used to measure voltage and amperage. A good one will measure 12,24,32 and 110 volts.
- Continuity Checker-has a test light that will illuminate of the circuit is operational. It consists of an alligator clip used for a ground and a probe that detects where there is a break or an "open" in the wiring system.
- Spare batteries-keep in a cool place and wrapped in plastic bags. If possible, bring them with you each time you go to the boat. Keep them in the refrigerator at home.
- Patience. Don't get wound up. Anger makes the job twice as difficult.