Looking for help diagnosing 2 problems: 1) Abnormal drain on the battery associated with the alternator connection to the motor, and 2) Abnormal drain on the battery (without alternator hookup) from just a small Garmin tied in.
Boat Info:
Boat: 2000 Catalina 18
Outboard Motor: 2019 Tohatsu MFS-6C
Garmin Echomap Plus 43CV with 4 inch screen (used for navigation, GPS info, and depth below keel readings via installed stern-mounted transducer)
Battery: Standard Marine 12V battery (age unknown, but at least 5 years old)
Problem 1 - the Alternator hookup.
When I bought the boat in the Fall of 2022, the previous owner had a nice setup. He had installed a small solar trickle charger on the stern, and installed the optional parts which connected an alternator to the motor with two bullet connectors (Red+/Black-) which could be plugged in or un plugged when the motor was in use or stored. This setup worked great to charge the battery when the motor was running, and then when not in use, the trickle charger kept the battery topped up.
About 3 months ago, I noticed that the bullet connector (Red/+) had failed and needed to be replaced. Most likely it had been like that for a while, but I never noticed anything wrong with the electrical as it still ran all my electronics. I bought the necessary marine wire and marine connectors to replace the failed bullet connectors and installed them. I started the engine and then used my multi-meter to check the voltage of the battery - much to my surprise, it was dropping like a stone - and FAST! I disconnected everything and started reading up on what this might be. I was 99% sure I had NOT accidentally switched the connections, but the you tube videos I watched said the most likely failure was that I'd blown the Rectifier Diode on the Alternator assembly. Once the weather cools off down here (I live in Northern Baja California, Mexico and the boat is full-time in a slip (in salt water), I have this plan of action in mind:
1) Follow the instructions to use my multi-meter to test the Rectifier Diode to see if it is indeed blown and whether I should replace that assembly. I have all the other connectors and wire, so I'm hoping that is a straightforward operation (although completely new to me)
2) If it is blown, go ahead and replace the Rectifier Diode assembly that is bolted to the motor, and then double-check the wires/connectors to the assembly before I fire up the motor to try to restore alternator charging of the battery when the motor is in use.
Anything else you'd recommend I try or look at?
Separate from problem 1, I now seem to have an issue with just running my small Garmin 43CV for longer than about 2 hours without it dying. This just started about a week ago. I tested the battery before turning anything on and it read 13.6V with the solar trickle charger plugged in. Once I turned on the Garmin, it began to slowly show voltage dropping until it eventually turned off. I was sailing at the time, so I hove-to and tested the battery - it read about 9.2V, which seems much lower than I would have expected after only a couple hours with one small device that pulls (according to the specs), 5W max power draw and a typical current draw of 0.5A (Max current draw of 2A). Confession - I know next to nothing about electricity, so I'm picking this up on the fly by looking at You Tube videos and reading instruction manuals. Any suggestions on where I start to troubleshoot this? I thought I would do the following:
1) Check the Voltage of the battery both with and without the solar panel connected to ensure the solar charger is working
2) Check the connection on the back of the electrical panel to make sure those connections have not corroded, fix if needed
3) See if I can find a date on the battery to see how old it is - perhaps the battery itself is failing
Other than that, I'm not sure what else to do.
Last couple notes: It has been SUPER HOT and humid down here. For example, last week when I had this issue, it was 100 degrees with about 60% humidity so the real-feel was 118. Perhaps I'm getting poor battery performance just because of the harsh heat?
Thanks for any insight or suggestions!
Boat Info:
Boat: 2000 Catalina 18
Outboard Motor: 2019 Tohatsu MFS-6C
Garmin Echomap Plus 43CV with 4 inch screen (used for navigation, GPS info, and depth below keel readings via installed stern-mounted transducer)
Battery: Standard Marine 12V battery (age unknown, but at least 5 years old)
Problem 1 - the Alternator hookup.
When I bought the boat in the Fall of 2022, the previous owner had a nice setup. He had installed a small solar trickle charger on the stern, and installed the optional parts which connected an alternator to the motor with two bullet connectors (Red+/Black-) which could be plugged in or un plugged when the motor was in use or stored. This setup worked great to charge the battery when the motor was running, and then when not in use, the trickle charger kept the battery topped up.
About 3 months ago, I noticed that the bullet connector (Red/+) had failed and needed to be replaced. Most likely it had been like that for a while, but I never noticed anything wrong with the electrical as it still ran all my electronics. I bought the necessary marine wire and marine connectors to replace the failed bullet connectors and installed them. I started the engine and then used my multi-meter to check the voltage of the battery - much to my surprise, it was dropping like a stone - and FAST! I disconnected everything and started reading up on what this might be. I was 99% sure I had NOT accidentally switched the connections, but the you tube videos I watched said the most likely failure was that I'd blown the Rectifier Diode on the Alternator assembly. Once the weather cools off down here (I live in Northern Baja California, Mexico and the boat is full-time in a slip (in salt water), I have this plan of action in mind:
1) Follow the instructions to use my multi-meter to test the Rectifier Diode to see if it is indeed blown and whether I should replace that assembly. I have all the other connectors and wire, so I'm hoping that is a straightforward operation (although completely new to me)
2) If it is blown, go ahead and replace the Rectifier Diode assembly that is bolted to the motor, and then double-check the wires/connectors to the assembly before I fire up the motor to try to restore alternator charging of the battery when the motor is in use.
Anything else you'd recommend I try or look at?
Separate from problem 1, I now seem to have an issue with just running my small Garmin 43CV for longer than about 2 hours without it dying. This just started about a week ago. I tested the battery before turning anything on and it read 13.6V with the solar trickle charger plugged in. Once I turned on the Garmin, it began to slowly show voltage dropping until it eventually turned off. I was sailing at the time, so I hove-to and tested the battery - it read about 9.2V, which seems much lower than I would have expected after only a couple hours with one small device that pulls (according to the specs), 5W max power draw and a typical current draw of 0.5A (Max current draw of 2A). Confession - I know next to nothing about electricity, so I'm picking this up on the fly by looking at You Tube videos and reading instruction manuals. Any suggestions on where I start to troubleshoot this? I thought I would do the following:
1) Check the Voltage of the battery both with and without the solar panel connected to ensure the solar charger is working
2) Check the connection on the back of the electrical panel to make sure those connections have not corroded, fix if needed
3) See if I can find a date on the battery to see how old it is - perhaps the battery itself is failing
Other than that, I'm not sure what else to do.
Last couple notes: It has been SUPER HOT and humid down here. For example, last week when I had this issue, it was 100 degrees with about 60% humidity so the real-feel was 118. Perhaps I'm getting poor battery performance just because of the harsh heat?
Thanks for any insight or suggestions!
