Article by Pat Schrawder
MAINTAINING YOUR BOAT’S ELECTRICAL SYSTEM
In last week’s issue, I talked about checking your equipment but I can’t stress enough the need to also check your boat’s basic electrical system. By that, I mean your batteries and the DC wiring coming from them to the rest of your equipment. A properly functioning 12-volt ship’s battery with the boat under way actually provides about 13.5 volts. Most equipment manufactured today requires 12 volts minimum. If your ship’s batteries are not supplying the correct voltage, your equipment will not work correctly. But that’s not the end of the story. There is a distinct difference between voltage and current and both need to be addressed.
Voltage can be best described as the availability of DC electricity for your equipment. Current is the network of delivery of the electricity to each item. It’s like saying that you have a bunch of cars gassed up and ready to go (voltage) but you need a system of roads to travel on that are in good working order (current). Just testing your batteries to see that they are charged up and in good condition is not enough. You need to make certain that the current can make it to where it’s going.
So how can you tell if your electrical system is okay? First, check your batteries after a full charge, with the boat running and alternators working. If you have roughly 13.5 volts at the battery terminals – good! Look at the terminals and make sure they are not corroded. Corrosion is the single most likely problem to occur. If they are corroded, clean them immediately and apply one of the many compounds available on the market to the terminals to prevent additional damage.
The next point to check is the main feed from the batteries to the circuit breaker panel or fuse panel along with anything in between such as a battery switch or isolator. Test the voltage again at these critical points and make sure you still have good voltage. Next, look at the circuit breakers and/or fuses to see if any of them are corroded or defective. Clean or replace as needed. Take a look at the wiring itself and check for any breaks in the outer sheathing that might have allowed moisture to enter. If you see any, you can replace the bad section but that puts a splice in the line that is a future weak spot. If possible, replace the whole wire.
Check all the power cords going to the individual pieces of equipment and look for “in-line” fuses. If there are any, take them apart and check once again for corrosion. Look at the plugs that go into the back of the set. As these are more exposed to the elements, they often show signs of corrosion. If you catch corrosion early enough, you can clean it off and put anti-corrosion compound on it to halt the process. If it goes too long, however, parts will need to be replaced. If you find corrosion on the plugs, make sure you also check the chassis jack on the equipment itself as there is a good chance it will also have problems.
The above procedure is the one I prefer. However, if you don’t want to check all of these points along the way or you can’t readily access them, you can by-pass this chain of events and go straight from your battery to the back of your equipment. Pull the plug and test for a minimum of 12 volts at the plug. The problem with this is, if you have a borderline situation, when the equipment is turned on, the voltage may drop below the required 12 volts and you will still have problems with your equipment operating properly.
Beyond corrosion, loose connections will have the same effect. On dead “give-away” that this is a problem on your boat is when equipment shuts itself off, especially in rough seas or high speeds when the boat is pounding.
This may all sound like something you just don’t feel like doing yourself. If so, get in touch with a professional who knows what they’re doing and who is familiar with the procedure. It may cost you a little bit of money but it is well worth the expense for the peace of mind that your boat’s electrical system is healthy.
Pat Schrawder and her husband Larry are owners of L&L Marine Electronics on Golf Course Road in West Ocean City.
