I have been having numerous problems with my electrical system, so I am interested in rewiring the DC system on my 1982 Hunter 30. The bilge pump switch on the DC panel works intermittently, the autopilot wires are either broken or corroded, the AM/FM radio will not play, a DC cabin fan comes and goes . . . So it seems to be a system-wide problem. 24 years of salt-air environment will do that, I guess. Is there any resource available to help me figure out wire gauges, wire lengths, routing of the harness, connectors, etc. I am not an electrician, so any help, no matter how basic, would be greatly appreciated.
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Try cleaning the connection first
marine wire does not normaly go bad unless you run too much current through it. The connections and ends however do tend to get corroded. you might be able to refurbish the connections and save the wire. A good way to ID the connections that are giving you trouble is to turn on the circuit and (don't try this with the AC circuits!!!) feel for a connection that is getting warm. That connection or the wire attached to it need to get cleaned. While this might not solve the problem it could make it a lot smaller one to fix. Good luck
marine wire does not normaly go bad unless you run too much current through it. The connections and ends however do tend to get corroded. you might be able to refurbish the connections and save the wire. A good way to ID the connections that are giving you trouble is to turn on the circuit and (don't try this with the AC circuits!!!) feel for a connection that is getting warm. That connection or the wire attached to it need to get cleaned. While this might not solve the problem it could make it a lot smaller one to fix. Good luck
DC problems
Bill has a good point. Increased resistance (read corrosion of connections) produces heat. One way I look for this is with an infrared heat sensor. You can get one at a NAPA store. Works pretty well once you determine the baseline operating temp of your circuits. The sensor is also very useful for troubleshooting cooling system problems. Be careful with the electricity and get some advice from an electrician if you continue having problems.
Bill has a good point. Increased resistance (read corrosion of connections) produces heat. One way I look for this is with an infrared heat sensor. You can get one at a NAPA store. Works pretty well once you determine the baseline operating temp of your circuits. The sensor is also very useful for troubleshooting cooling system problems. Be careful with the electricity and get some advice from an electrician if you continue having problems.
Thanks a lot, guys
I appreciate the advice. I have no doubt that I can do the necessary work, but I wanted a guide of some sort. I requested help from Hunter Customer Service, but got no response. Fred, your photo is impressive, but when I look at something like that, I'm lost without a wiring diagram or some instructions. Can you recommend a book? I was hoping for wiring diagram from Hunter... Thanks again for the help so far.
I appreciate the advice. I have no doubt that I can do the necessary work, but I wanted a guide of some sort. I requested help from Hunter Customer Service, but got no response. Fred, your photo is impressive, but when I look at something like that, I'm lost without a wiring diagram or some instructions. Can you recommend a book? I was hoping for wiring diagram from Hunter... Thanks again for the help so far.
Wire size
DC systems are easy to wire. Just pick the right size wire (See link) and run a positive wire to the device from the switch. The ground is a constant feed. Run one good size ground wire to a bus bar for a group of devices in the area and then coat that bus bar for corrosion resistance (make sure this bus bar doesn't have an electrical connection to the fiberglass (continuity)). It's kind of stupid to run 10 ground wires to the cockpit for 10 different devices like hunter does. The odd ball: some things do it the opposite and have a constant positive feed and the ground wire goes though a switch; a refrig temp switch is a good example. The only thing that I've seen on boats that gets tricky is the refrig and the instriments that all communicate with each other but even those can be figured out with time and understanding how the system(s) work.
DC systems are easy to wire. Just pick the right size wire (See link) and run a positive wire to the device from the switch. The ground is a constant feed. Run one good size ground wire to a bus bar for a group of devices in the area and then coat that bus bar for corrosion resistance (make sure this bus bar doesn't have an electrical connection to the fiberglass (continuity)). It's kind of stupid to run 10 ground wires to the cockpit for 10 different devices like hunter does. The odd ball: some things do it the opposite and have a constant positive feed and the ground wire goes though a switch; a refrig temp switch is a good example. The only thing that I've seen on boats that gets tricky is the refrig and the instriments that all communicate with each other but even those can be figured out with time and understanding how the system(s) work.
Franklin's right.
All wiring (DC) is just running a positive wire to the load. In the picture of my panel you are looking at SIMPLICITY, not complexity. It should be illegal to wire a yacht any other way. In fact it's so simple that I did it all in my head. No diagrams. Only a written list of the number tabs seen on the ends of the red wires. And be sure to do like Franklin says for your ground buses too. I can't recommend a specific book. I thumbed through a couple of them looking for ideas but I already knew this stuff. In fact I think you can find all you need online now that I think about it. One more thing, when you see how simple this stuff is, it's then fun. Oh, also be sure to invest in quality crimping tools and cutters. Not one of those do-it-all pliers.
All wiring (DC) is just running a positive wire to the load. In the picture of my panel you are looking at SIMPLICITY, not complexity. It should be illegal to wire a yacht any other way. In fact it's so simple that I did it all in my head. No diagrams. Only a written list of the number tabs seen on the ends of the red wires. And be sure to do like Franklin says for your ground buses too. I can't recommend a specific book. I thumbed through a couple of them looking for ideas but I already knew this stuff. In fact I think you can find all you need online now that I think about it. One more thing, when you see how simple this stuff is, it's then fun. Oh, also be sure to invest in quality crimping tools and cutters. Not one of those do-it-all pliers.
Thanks Fred and Franklin
I appreciate your help. I know it will be fun to add another skill to my arsenal, and to gain the satisfaction of maintaining my boat. The wire gauges and the tip on tools will help a lot. As I said, I'm not an electrician (actually, I'm an accountant). I really am not looking forward to a long, involved project, in the cabin, in the heat of the south Alabama summer. Thanks again.
I appreciate your help. I know it will be fun to add another skill to my arsenal, and to gain the satisfaction of maintaining my boat. The wire gauges and the tip on tools will help a lot. As I said, I'm not an electrician (actually, I'm an accountant). I really am not looking forward to a long, involved project, in the cabin, in the heat of the south Alabama summer. Thanks again.
Disagree with Franklin...
on his common ground approach. Not only is it contrary to ABYC conventions, it could lead to a serious problem. What wasn't said was that the "good size wire" had better be sized to carry the current load of all the area devices it's intended to serve. If there's six devices that add up to, say 10 amps of use (halogen lighting, etc), then the AWG wire size serving the bus bar should be sized to carry that load with a minimum of 25% margin for the distance between the bus bar and the negative battery connection. If the individual power feeds (red wire) are 14 AWG, the bus feed could possibly need an 8 or 10 AWG negative feed to/from the bus bar. The need to isolate electronics and any digital devices to their own power/"common" connection is especially important for a digital circuit's "hi-low reference" (chip on or off). Switching a light or motor on or off on a circuit containing a GPS or autopilot as well could cause a voltage differential that would affect their operational reliability. Troubleshooting such a problem with common grounding circuitry could be quite a challenge. Lastly, fiberglass is a non-conductive so I need to have the "continuity" issue explained. Just MHO...
on his common ground approach. Not only is it contrary to ABYC conventions, it could lead to a serious problem. What wasn't said was that the "good size wire" had better be sized to carry the current load of all the area devices it's intended to serve. If there's six devices that add up to, say 10 amps of use (halogen lighting, etc), then the AWG wire size serving the bus bar should be sized to carry that load with a minimum of 25% margin for the distance between the bus bar and the negative battery connection. If the individual power feeds (red wire) are 14 AWG, the bus feed could possibly need an 8 or 10 AWG negative feed to/from the bus bar. The need to isolate electronics and any digital devices to their own power/"common" connection is especially important for a digital circuit's "hi-low reference" (chip on or off). Switching a light or motor on or off on a circuit containing a GPS or autopilot as well could cause a voltage differential that would affect their operational reliability. Troubleshooting such a problem with common grounding circuitry could be quite a challenge. Lastly, fiberglass is a non-conductive so I need to have the "continuity" issue explained. Just MHO...
Dan
Fiberglass does carry a current. Don't believe me. Take a wire and connect it to your positive battery terminal and the other end to any place on the hull's fiberglass. Then go and use a multimeter and check for voltage on the other side of the hull. Now, as for the common ground...every boat DC system has a common ground...it's one system. The only difference is where the bus bar is and how many bus bars and how many wires you got running around. Every single ground wire in your 12 volt DC system is grounded to the negative battery terminal, one way or another. So any short you got is going to effect the whole system.
Fiberglass does carry a current. Don't believe me. Take a wire and connect it to your positive battery terminal and the other end to any place on the hull's fiberglass. Then go and use a multimeter and check for voltage on the other side of the hull. Now, as for the common ground...every boat DC system has a common ground...it's one system. The only difference is where the bus bar is and how many bus bars and how many wires you got running around. Every single ground wire in your 12 volt DC system is grounded to the negative battery terminal, one way or another. So any short you got is going to effect the whole system.
Franklin...
that's one for Mr. Wizard! Now I can't wait to get back to the boat to try that out. I suspect that an electrical field is being detected, not actual current flow. If it were so, we could wire things just like in a car! If I get a reading I'll have to try it separately on hardened resin and glass mat to see which one is the conductor.
that's one for Mr. Wizard! Now I can't wait to get back to the boat to try that out. I suspect that an electrical field is being detected, not actual current flow. If it were so, we could wire things just like in a car! If I get a reading I'll have to try it separately on hardened resin and glass mat to see which one is the conductor.
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