Alternator or other electrical problem ?
I have a 1972 Kona jet boat with a 455 olds. I am the original owner. Last year I had all of the gauges and wiring replaced due to a short in the electrical system that couldn’t be found. That problem was cured. However since those repairs were done late last summer and the boat was stored for the winter I didn’t release there was another problem that was starting to surface. Prior to going on vacation I replaced the battery with a new one and went to the local lake to make sure all was well mechanically. After starting and stopping the battery went dead. Prior to the battery going dead I noticed the voltmeter to read a couple of “hairs” above 12. I assumed the original 2-wire alternator (Motorola Type B 35 AMP) with the regulator attached to the backside of the alternator had gone bad. I then purchased a brand new (no rebuilt) Prestolite/Leece-Neville alternator that was a replacement for the original Motorola alternator. Again, back to the lake. After starting the engine the voltmeter read a couple of “hairs” above 12. After stopping and starting the voltmeter read below 12 and then eventually to 10. I took the alternator back to where it was purchased and they told me it would be replaced if it were bad. The alternator was tested and I was told it was ok. Any ideas or direction would be greatly appreciated for this novice. Thank You.