Re: Low Voltage at Sea Ray Cuddy Helm
Voltage delivered to the helm of my 1984 Sea Ray cuddy is just over 12 [Volts]. The [terminal voltage] measured at the battery is 14.2 [Volts]...
There will always be some voltage drop in the power distribution of your 12-Volt battery. The voltage drop is determined by the resistance in the power distribution circuit and the current flowing. You report seeing a drop of 2.2-Volts, which is a substantial voltage drop. This is very unusual, especially because you seem to have this voltage drop with only modest current flowing, perhaps only the current needed to operate your voltmeter.
It would be unusual that so much voltage drop could occur with such modest current flow due entirely to resistance. Another cause of voltage drop can be very bad connections, which are made between conductive metals but where a layer of oxidation or semi-conducting material has formed, and which are operating almost like a diode or rectifier instead of a conductor. Really bad connections can have a voltage drop across the connection that is higher than expected just due to resistance. Sometimes these connections will reestablish themselves when more current flows.
Since the wiring and electrical components on your boat probably date from 1984, they are almost 30-years old. The service life of electrical components in power distribution is really not forever. It is time to overhaul the electrical power distribution on your boat.
If the copper wire used for the power distribution from the primary power to a secondary power distribution panel is in good condition, that is, if the wire was originally a high-quality tinned copper wire, there is no sign of ingress of water, there is no damage to the insulation, and if the wire appears to be in as-new condition, you could re-use those cables, but I would recommend cutting off any ring terminal connectors and installing new ones. If you have any doubts about the condition of the wire, just replace it. Considering the age of your boat, the wire may not be of the same quality as can be found now.
For branch circuit wiring I recommend getting new wire. The cost is not a burden, and using new wire will allow you to upgrade to the best marine-grade wire, and to use the proper color-code for insulation. Many older boats do not conform their wiring to modern color codes for wire function.
You can sometimes restore ring terminal connectors which have become pitted or oxidized by using a solvent like WD-40 and burnishing the connector surface by wet sanding (with WD-40) using 600-grit emery cloth. You want to remove oxidation and return the surface to a smooth metal finish. Of course, this sort of repair is of no value if the ring-termimal-to-wire connection is oxidized. If there is any sign of oxidation in the ring-termimal-to-wire connection, it is best to cut off the ring terminal connector and install a new one. By the way, I prefer to solder these connections, although that can sometimes be controversial.
To buy wire and electrical wiring accessories like ring terminal connectors, I recommend shopping for them on the internet. There are several vendors on the internet that specialize in selling marine-grade power wiring and accessories, and the prices offered are much more attractive than the prices for similar products found at many boat supply stores. I have ordered wire and accessories from GENUINEDEALZ.COM and had very good luck. I often received ANCOR-branded wire at a fraction of the price that ANCOR-branded wire is typically sold in marine stores.
For power distribution devices and accessories, I have found the BLUE SEA SYSTEMS devices to be very good. These can also be purchased on-line at substantial discounts.
For guidance in re-wiring the electrical power distribution, I have written an article on that topic that you might find useful to read. See
http://continuouswave.com/whaler/reference/boatWiring.html
I have also written a narrative of my own re-wiring. You might find it useful to read, too:
http://continuouswave.com/ubb/Forum6/HTML/003179.html
