Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Hello and thank you for your question. My name is James.
Can you try a voltage drop test from the center of the negative battery post to any of the body ground bolts that you can access in the engine compartment? Are you able to see the negative ground cable where it attaches to the body and the engine to check for corrosion? How about the positive cable at the starter? I'm guessing there's no corrosion or loose connection at the alternator, since you were in the area recently.
Does the engine run now? If so, can you test voltage across the battery when it's running to see what the alternator output is?
Is it the same when the cables get hot? Is there any way you could upload a picture of the cable repair that you made?