A Big thank you with some questions. (Electrical Questions)

Clarime

Member I
First a big thank you to all the advice that you gave me and others that I read over to get my answers. A special thanks to Sailing42 (John) who helped me find the routing of my mast wiring so that I could use the original path.
During the process of trying to fix my wiring I found many troubling and puzzling things. Automotive but joints (not Marine) and poorly constructed splices, miscellaneous wires and connections. Wires grounded all over the flywheel cover?? (Lazy). In the end I re wired probably 80 to 90 percent of the boat. Which leads me to my questions.

Question One: When replacing the alternator I found an extra wire connected to it (the exciter leg). After tracing the extra wire I found it was connected to The VHF radio and Auto pilot wiring that was also connected to Accessories 1 Switch which has power of its own. In all the research I did I couldn't find any reason for this.
Seemed wrong so I disconnected it!

Question Two: In the process of sorting the rats nest I found the main ground that goes to water. I am wondering how and where this should be connecting to my main wiring harness.

Last question: I connected my new Chart-plotter to my VHF radio. Is there anyway to test to see if it is transmitting my position through the radio?

Thanks in advance for your help and advice.
Chris
 
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toddster

Curator of Broken Parts
Blogs Author
1. Sounds pretty sketchy to me, as described, but check to make sure that your alternator is still working. You do need to supply voltage to the exciter terminal or you won't get any amps out. On a gas engine this would usually be from the coil or the "ign" terminal.

2. The main ground for your DC system should be a lug on the engine block. There are other sorts of sea-water grounds that might be present on a boat for completely different reasons, and would not be connected to the DC system. Have a look at this link. https://www.westmarine.com/WestAdvisor/Marine-Grounding-Systems

3. If I understand this correctly, you want your chart plotter to send GPS data to the NMEA 0183 port on your radio, for DSC position reporting. You will probably have to read your radio manual. If your radio has a position display (e.g. Standard Horizon GX series) the Lat/Long should show up when the radio is receiving the data. Other radios have an "error" beep if you try to use DSC without GPS input. Or without your MMSI. If you think everything is hooked up correctly and your radio has no position display, you can try to make a DSC test call.
https://www.navcen.uscg.gov/?pageName=DSCTesting
http://continuouswave.com/forum/viewtopic.php?t=3207
 

supersailor

Contributing Partner
After multiple electrical failures in my first year of ownership, I threw away the electrical "system" on Terra Nova and designed my own. I haven't had a failure since. The obvious thing was that most of the "mickey mouse" work had been done by pros (I have the receipts to prove it). As Christian says ":We don't want to pay for quality work so we don't get it." An example is there were seventeen different grounds on the engine block. Gad! The original wiring was not much better with trailer plugs between the panel and the engine. The best thing you can do is rewire any of these older boats with tinned wire, shrink fit terminals and thoughtful planning.

P1000506-001.JPG
 

Clarime

Member I
Thanks for all the advice

1. Sounds pretty sketchy to me, as described, but check to make sure that your alternator is still working. You do need to supply voltage to the exciter terminal or you won't get any amps out. On a gas engine this would usually be from the coil or the "ign" terminal.
Thanks Toddster, The exciter leg is connected to the coil like the original and new alternator. I was just wondering if anyone had heard of a reason for the other wires (Radio and Autopilot power) to be connected to it. As I thought there doesn't seem to be any good reason.

Thanks for the links. The one about the neutral wires cleared things up for me and also pointed to more work that I need to do.:eek:
 

supersailor

Contributing Partner
Thanks. It does take a little bit of study but simple DC wiring is not too difficult to understand. I began my study when I had a motor scooter in school and it broke. I could buy gas or have it fixed but not both. I chose to buy gas and the fix worked. A little bit later I took an MG in to be tuned for back then a princely sum of $110. It didn't run that great afterword. I tinkered with it and got it to run much better. My faith in the pros never quite recovered.

The ability to repair things while sailing and out of touch with the mechanic is invaluable. Just listen to the old wag who said. "If he can do it, I can do it" and its true.
 
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