Troubleshooting mast lights.

[Warren Kaplan]

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)



Setsail728@aol.com

[len]

warren

electrical engineers will cringe, but i usually check circuits by putting a little battery, e.g. a D cell, into the circuit at one end, and checking for voltage at the other end - i wouldn't be surprised if
you could dimly light the bulb with two or more D cells in series - if the bulb lights, you don't have to check anything else in the mast -

len



md.frel@nwh.org

[Bill Goldsmith]

Warren,

Sounds like we're dealing with similar issues, except my problem is on the anchor light. I will be reading with interest all responses as to the best way to troubleshoot mast lights.

Question: Does it bother anyone else that the standard CD deck light/steaming light always works as a unit? Shouldn't there be two switches--one for the deck light and one for the steaming light?

As it is, when motoring at night, the deck light is always on.

Bill Goldsmith
CD27 #173 Second Chance

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

goldy@bestweb.net

[Bill Goldsmith]

Warren,

Sounds like we're dealing with similar issues, except my problem is on the anchor light. I will be reading with interest all responses as to the best way to troubleshoot mast lights.

Question: Does it bother anyone else that the standard CD deck light/steaming light always works as a unit? Shouldn't there be two switches--one for the deck light and one for the steaming light?

As it is, when motoring at night, the deck light is always on.

Bill Goldsmith
CD27 #173 Second Chance

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

goldy@bestweb.net

[hud smith]

You can take the bulb out, then check for continuity between the ends of the plug and the mast. Shake or roll the mast to move the wires around inside. You can tape one lead to the mast to do this. If you want to get a reading on the resistance of the mast, run a copper wire outside the mast, tape it to the mast by the light, and bring it down to the base. Cut the wire at that length and touch the probes to the wire and the mast. If you remove the bulb, there should be infinite resistance in the circuit. Put the new bulb in, and check for circuit. Yes, there is resistance in the bulb, but not much- check it on the new bulb before you put it in. Check for continuity between the light fixture and the mast also. You're just looking for a leak to the mast, or a broken circuit(wire) -mess with it a while and you'll see what it's doing.

[Joe Sankey]

I believe there are two switches; one for deck and one for steaming. If not, perhaps one of the switches on your vessel was used for something else. On my various CDs there was no provision for an anchor light. On our current 30, one was mounted, but aftermarket, using a spare breaker. Obviously not familiar with your boat, I'm making assumptions, but it may be your problem is at your breaker box.
Joe Sankey
CD 30 Slow Dance

Warren,

Sounds like we're dealing with similar issues, except my problem is on the anchor light. I will be reading with interest all responses as to the best way to troubleshoot mast lights.

Question: Does it bother anyone else that the standard CD deck light/steaming light always works as a unit? Shouldn't there be two switches--one for the deck light and one for the steaming light?

As it is, when motoring at night, the deck light is always on.

Bill Goldsmith
CD27 #173 Second Chance

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

[sloopjohnl]

unless you pull your mast every year this time, why not throw in two new bulbs and put that factor out of the equation now and for a few years down the road if your wiring is in good shape.

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

[JimL]

12 Volt circuits with multistrand wire are prone to wire deterioration. Using an ohmmeter may not identify a problem wire. Why? Because the ohmmeter passes such low current, that a good strand (out of many) will handle the ohmmeters load.

Here's how to check individual wires for resistance under load.

1. Make up a long jumper wire for your voltmeter.

2. At the supply end of your wire (the one you are testing) connect a 12 volt trouble light in series, to your battery voltage.

3. Apply 12 volt power to the trouble light, then ground the other end of the wire being tested (the test light is in series with the wire). It's ok to run a length of wire to provide the ground. Our next step will explain why.

4. Connect the negative terminal of your voltmeter (set on Volts, NOT Ohms) to the suspect wire, where it is connected to the test light (after the light, which must be lit, or the circuit is broken).

5. Connect the positive lead of the voltmeter to the other end of the wire, where it is connected to your added or temporary ground lead or point.

6. The voltage you read is a reflection of the resistance of that section of wire, UNDER LOAD. Typical voltage drop on a good wire will be less than .1 volt (often less than .05 volt!) If the wire is undersize for the job, you'll see more voltage drop.

7. You may see as much as .1 volt drop across connections and/or relays/switches. Use this method to test an entire system, that may have several connections, in series. Too many connections, or corrosion at contacts, will be easy to identify.

8. Use this method, one at a time, for many wires in a bundle. A problem wire or connection will "stick out like a sore thumb"!

For you folks with the luxury of electric starting engines, use this method on the power and ground cables for the starter. .3 volt drop is not uncommon, but more than that may make the starter run too slow.

One last comment...if you find a connection turning green, when others around it are ok, you've may have a circuit with a little "floating ground". Connections in that circuit may act like "positive ground" resulting in rapid oxidation of the copper.

Hope this will be of some help, to someone.



leinfam@earthlink.net

[JimL]

The starter cables are not tested using a test light. They are testing while cranking the starter. Put the negative terminal of the voltmeter on the battery positive post. Put the positive terminal of the voltmeter on starter terminal. The (-) voltage read, while cranking is the voltage drop under load. No, it will not blow up your voltmeter unless you set it on amps.....pay attention.

Thank you.

[Larry DeMers]

The Steaming and Deck lights are on two separate switches, when they leave the factory..at least it is that way on every CD I have seen. You may have a Previous Owner installed "Feature", or there may be a short between the two power leads to the two separate circuits.

Check the breaker panel..I'll bet you do have one for each separate function.

Cheers,

Larry DeMers
s/v DeLaMer
Cape Dory 30

Warren,

Sounds like we're dealing with similar issues, except my problem is on the anchor light. I will be reading with interest all responses as to the best way to troubleshoot mast lights.

Question: Does it bother anyone else that the standard CD deck light/steaming light always works as a unit? Shouldn't there be two switches--one for the deck light and one for the steaming light?

As it is, when motoring at night, the deck light is always on.

Bill Goldsmith
CD27 #173 Second Chance

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

demers@sgi.com

[Tom]

For what it's worth here's my two cents. When circuits go bad it's usually not in the wires, but in the connections at the ends. Before you go messing with trying to read ohms with a meter and all that, you might take the plug off the bottom and clean the wires. Then take the light apart and clean all the conncetions and wires there. Remove the bulb and shine the contacts. Shine the copper blade that holds the bulb in and then bend it so it makes good contact (they tend to lose their spring with time). Now take a car battery and hook the wires at the bottom of the mast to it. Chances are you will have solved your problem and you won't need a meter at all. If this isn't your problem it's good maintenance anyway so you haven't wasted your time.

If that doesn't solve it hook the battery up at the bottom and take your meter up to the light fixture. You should read the same voltage at that end of the wires as you have on the battery (the voltage loss is minor unless you have a very good meter). If you have 12 volts there and the bulbs are good then you may have a short somewhere and can proceed with the ohm testing, but if the wires are bad you probably want to take them all out and replace them with pre-tinned marine wire (nothing else will do) anyway. Why screw around with those old copper wires trying to find a short and trying to figure out the resistance in the mast and all that. If the problem is in the wiring I'd just rip it out of there and start with new tinned wire that you know is good. While you're at it run a wire to the masthead in case you want to put a tricolor or a strobe up there some day. That's what I did.

BTW wires slamming against the mast and keeping you awake at night is a problem with aluminum masts. There are a lot of posts about this in the archives that you might want to look over. I ran a PVC pipe up the mast to solve the problem for me and it's worked fine. I also cut the plug off and soldered regular spade lugs on my wires and then installed a terminal block in the mast step well to hold them. I put lanolin on them to keep them bright and they are easy to see and get to. It only takes a second to unscrew the wires and if it comes to that it's easy to put the probes of your meter on them to test circuits or feed 12 volts to them. My mast is stepped through the deck onto the keel, of course.

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

TomCambria@mindspring.com

[Larry DeMers]

Hi Warren,

Thought I would check in with the board and see whats up..found a question I could help with maybe.
The Steaming/Deck light has three leads..one ground and two hot leads. If neither of your lights on this fixture work, then there is a chance that the problem is the ground wire, as it is common to the two circuits.

What I do to troubleshoot mast wiring is to use my ohmmeter with some clip-on leads. I find and identify the cable carrying the voltage to the steaming/deck light, then setup a little table on a piece of paper, that has the 3 possible combinations that the three wire cable could have (ie: A to B, A to C, and B to C). Then I clip one lead on lead A (your choice which one it is, but it has to stay 'A' for the duration of this test), and probe lead 'B', then note the resistance. Repeat for lead 'C'.

You are correct that the standard 10W incandescent bulb will have about 8.3 ohms resistance. The total loop resistance with wire included will be slightly higher than this..maybe 9 ohms total. The exact number depends on contact resistance, so a significantly higher reading indicates a poor contact in the base of the bulb holder probably.
In checking the three wires, you will hit two that read around 9 ohms each, and one combination that reads around 18-20 ohms. The two 9 ohm leads go to the two lights..while the 18-20 ohms will be the two lamp filaments in series with each other, going thru their common grounds.

Next check each lead separately for shorting to the mast. Clip one ohmmeter lead to the mast itself, and then touch all of the three leads sequentially, and look for a reading other than open circuit. If there is a reading, then you have a shorted wire to the mast.

If these test fail to show up a problem, then the next question is the connector itself, followed by the boat wiring.

Hope this helps..

Cheers, and Happy Turkey Day ya all~!

Larry

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

demers@sgi.com

[Warren Kaplan]

Thanks to all who helped me out here. I see there are many good ways to "skin this mast light cat". Hopefully, the problem will be obvious. I also apologize for my mindless math error in my original post. 8.4 Ohms - .13 ohms = 8.27 Ohms. Not the 7.1 I posted. A matter of a decimal point problem. I'll not be able to work on this problem until after Thangsgiving but if I have any problems working this all out, all of you will be the 2nd to know!

Warren Kaplan
S/V Sine Qua Non
CD27



Setsail728@aol.com

[Warren Kaplan]

Question: Does it bother anyone else that the standard CD deck light/steaming light always works as a unit? Shouldn't there be two switches--one for the deck light and one for the steaming light?

As it is, when motoring at night, the deck light is always on.

Bill Goldsmith
CD27 #173 Second Chance

Bill,
My CD27 has separate switches on the distribution panel for the two mast lights....as others have illuded to. Since my boat is only 7 boats older than yours, and built in the same year, I assume your panel was modified. If you look at my panel you KNOW mine wasn't!! Probably at the same time the bowsprit and larger engine were installed on Second Chance.

Warren Kaplan
Sine Qua Non
CD27 #166



Setsail728@aol.com

[Will W.]

It sounds like someone must have modified the wiring somewhere. Now you are displaying two forward facing white lights at the same time I beleive. If this is so, you are telling people you are a much larger vessel coming straight at them. Unless they decypher the eroneous lighting.
According to Nigel Calder, another common Nav. light mistake is to have the Anchor and Bow lights on the same switch. The proper set up is to have the running lights the, bow/masthead light, the anchor light and any deck lighting each get their own switches. anything else will result in being forced to send an eroneous signal at some point. This info all comes from Chapmans (love it)

Will Wheatley
Suzi Q
CD25


Warren,

Sounds like we're dealing with similar issues, except my problem is on the anchor light. I will be reading with interest all responses as to the best way to troubleshoot mast lights.

Question: Does it bother anyone else that the standard CD deck light/steaming light always works as a unit? Shouldn't there be two switches--one for the deck light and one for the steaming light?

As it is, when motoring at night, the deck light is always on.

Bill Goldsmith
CD27 #173 Second Chance

Now that Sine Qua Non's mast has been unstepped, I have a chance to check the deck light/steaming light that has been inoperative. Right now, I just want to talk about the mast side of the wiring as I will check the boat side in the spring when the shrink wrap comes off. First, let me say that I've read a couple of sailboat electrical books on this so I'm not totally unfamiliar with what I want to do. Obviously, with the mast unstepped I'll be able to get at both bulbs and put my trusty ohmmeter on them to see if they are okay. I'll also check the plug to make sure there's no corrosion and all wires are connected as they should be. On short stretches of wire when doing continuity testing the ohmmeter should read zero if all is okay. In one book I read, they advised disconnecting the plug at the mast base when everything IS working okay to get a reading with an ohmmeter so you know what "normal" is. I never got the chance to do that. They mentioned that #12 wire generates .16 ohm resistence per 100 feet of wire so a 40 ft mast (80 feet of wire up and back down) would be .8 X .16 or about .13 ohms. Now here is were I have a little trouble and why I'm asking this question. They show an illustration of 3 conditions. First, and open circuit, usually blown out bulb with an ohmmeter reading of 0.L which is understandable. Then they show a condition of a short circuit to the mast with an ohmmeter reading of 0.4 ohms. Okay, short circuit, as it says, not much wire and therefore not many ohms generated. Then they show a "normal" condition of the circuit with a reading of 8.4 Ohms. I understand that .13 ohms comes from 80 feet of wire in the mast in their example. I can only assume that the additional 7.1 ohms comes from the resistence in the bulbs. Right? Wrong? I have a CD27. Mast height in 38.5 feet. If everything on the mast side is in working order, what should the reading on my ohmmeter be for the whole circuit? On their example it was 8.4 ohms. What should I be lookin' at. I will of course check the entire fitting, not just the bulbs as the problem could be in corroded contacts etc. Thanks for patiently reading this.

Warren Kaplan
S/V Sine Qua Non
CD27 #166 (1980)

willwheatley@starpower.net