Hey all, newby to the forum and newby to owning a boat. I've spent a lot of time in the sun on my boat over the past few weeks, unfortunately not on the water. I bought the boat as a project. Has an inboard 4.3 that didn't run when I got it. The long block and intake were tranplanted from a 1990 Chaparral and all other electrical components were transferred over from the 1996 4.3. Overall, a pretty clean job for what I know about boats. A carb rebuild, new plugs & wires, fuel pump, oil change and fresh gas and I was able to get it to fire and run pretty decent. I replaced the gauge oil sender and fuel sender to get the gauges working but the volt gauge didn't seem to be working. The alternator wasn't charging so I replaced that as part of an electrical system clean up. This is where the trouble started. Before starting it after the alternator replacement, I cleaned up some wire routing and replaced some component terminals with weather-seal terminals. I had a couple of stray black wires that I assumed were ground wires so connected them to the ground junction in the center rear of the engine compartment. After doing all of this, I went to reconnect the battery at which time the two wires I connected to the ground block immediately smoked and glowed from the block into the engine harness. I thought maybe they were powered circuits that had black wires for some reason but I traced them into the engine harness to the ground junction for all engine components. I'm really puzzled as to why they lit up like a fuse given they were indeed ground wires that I essentially re-grounded to the block. After cleaning that up, I discovered the guy I got it from didn't add the 90A fuse at the starter and had the 50A circuit breaker red wires connected without a breaker. I bought new ones and installed them per factory wiring. I now have no power to gauges or starter when I turn the ignition switch on/crank. The switches for the bilge pump and fan are lit and both work with key on. The outdrive will go up and down. I wiggled the shifter around while cranking and nothing. I flipped the emergency kill switch while cranking and nothing. Although I've read that neither of these would affect the gauges. I jumped the secondary solenoid and the engine cranks but no fuel pump or spark which is probably normal. I bought a new secondary solenoid and ignition switch but the problem still exists. I found a wiring diagram for the engine online and everything is connected correctly as far as I can tell. Back to the ground issue. I got the meter out and have continuity from the engine harness to the battery. I have no resistance through the connector or through the harness on the engine side to ground (with the master connector disconnected). I have no resistance on the body harness side through the ground terminal on the connector. However, I have over 4 ohms of resistance from the ground wire just past the body side engine harness connector to the battery. This is where I'm lost. I can't find a wiring diagram to show me the wire routing once it leaves the engine harness connector so don't know where to look or what may be the issue. The harness disappears deep into the engine compartment and I'd rather not tear it all apart to trace it's routing if I can help it. A wiring diagram would be very helpful here. I bought this boat super cheap and really want to get it on the water but I've exhausted my knowledge of boats and hours of online searching are yielding no results. The fuse and circuit breaker were necessary. The solenoid and ignition switch were cheap so worth a shot but I don't want to keep throwing parts at it hoping to fix it. I'm a little concerned that I reversed polarity and smoked some expensive components but that doesn't make sense given I grounded wires that were already grounded, which also doesn't make sense. So...1 - Does anyone have the diagram that includes everything beyond the engine harness? 2 - Any ideas on where to look next.