POWERBOATER’S GUIDE TO ELECTRICAL SYSTEMS
Installing a GPS Receiver
tion here is simple: Either periodically wipe down the face of the transducer with a wet cloth to clear the surface, or prevent the fouling in the first place Whether you’re installing a conventional GPS receiver by using transducer antifouling paint, available at or a chart plotter with an integrated GPS sensor, you West Marine and other marine supply houses. I essentially need to make the same considerations as don’t recommend that conventional bottom paint you would with all other electronic devices. One thing that will make a minor difference in the installation of be used to protect these surfaces. If your fish-finder or depth-sounder stops work- your GPS unit is whether or not you select a standard ing altogether or begins to send mysterious signals or differential GPS (DGPS) configuration. Like all of the equipment discussed so far, the lothrough your display, there are several additional cation for the display unit must be carefully considsteps you can take to isolate the problem. First, ensure that the display unit is getting power and has a good ground, just as you would for GPS Antenna any electrical appliance. Use your multimeter, set up to read volts, to make sure the voltage May have a is not below your unit’s minichassis mum threshold. If it is, deterground Calibrated Factory mine why by using all of the Supplied Cable methods described throughout this book. Checking your transducer may require hauling the boat so DC + you can get at the face of the unit. If you’re up to it, a brief DC underwater swim may be all that’s needed. With the sounder Fig. 12-13. Wiring layout for a standard GPS installation. turned on, you should hear a ticking noise coming from the transducer as it attempts to transmit its signal. If you don’t GPS Antenna hear a ticking sound, the transducer is faulty. Also, if you rub the palm of your hand across May have a chassis the face of the transducer while ground someone watches the display, DC Fixed length cable they should get a fuzzy reading across the screen. If not, the DC + transducer is at fault and needs to be replaced. Naturally, you should also become familiar DC + with the controls and calibration settings for your fish-finder DC and depth-sounder and be sure they are set up properly. Fig. 12-14. Wiring layout for a differential GPS (DGPS) receiver. 190
