Re: 1988 bayliner capri BR
Wiring diagrams/schematics are simply a pictorial of the arrangement of wires. Each line represents a wire. Whether on a boat, in a car, truck, airplane or the space shuttle, current flows from a source (normally a battery, through a main fuse or circuit breaker within six inches of the battery, to a fuse or circuit breaker panel. From there the circuits branch out (each fuse is protecting a circuit) to a device via its switch. From the device, current flows back to the battery on the ground wire. Generally there is a ground buss (connection point) at the helm or built into the fuse/breaker panel where all the ground connections are made. Then one larger wire connects that point back to the negative terminal on the battery to complete the current path. In your case, you need to start at the battery. You should find a red wire and black wire of either #8 or 10 gauge. That is the main feed to the fuse panel. Check for a fuse or circuit breaker in the red wire close to the battery. Make sure the wires are connected and the fuse or breaker are ok. Use your voltmeter (neg on battery post, POS test lead on the battery side -- then the load side of the fuse or breaker. No voltage? Battery is dead or the wiring is bad. If you have voltage then follow those wires to the fuse panel. If you have no voltage into the panel, either the ground or the feed is disconnected or broken somewhere along the line. When you do succeed at getting +12 volts to the horn, make sure it is grounded. If it still doesn't work, remove it and connect directly to a battery. If it still doesn't work, it's toast. A bad switch will prevent 12 volts from reaching the horn. Again -- use the voltmeter. red lead on the INPUT side of the switch, black lead to KNOWN GOOD GROUND. Then press the button with the red lead on the load (horn) side of the switch/button. No voltage means the switch/button is toast.
Here is a simple diagram: Just pretent the light is the horn.