Dave You always seem to have plentiful advice and input, and usually with good humor, so... the mastlight on my 98 240 doesnt work. Checked and rechecked the deck plug in and confirmed battery was OK by turning on other lights. Assume I will have to drop the mast and replace bulb. Unfortunately the owner's manual gives a Hunter part number making it hard to order from my West Marine catalogue. Your sage input on this issue appreciated. We are but a few short weeks from the sailing season in our neck of the woods and its time to be ready! Thanks Bill Welsch s/v "Renewal"
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Multimeter it
Go get a ten dollar volt/ohm meter and check the continuity before you pull down the mast. There should be continuity between one of the posts to the other two and none between those two. The little multimeter is well worth the money for all sorts of jobs. If this checks out you the bulb is most likely not the culprit. On mine the contacts at the deck plug need to be cleaned often. Perhaps the fuse, the switch or the connection to either could be loose. There are two bulbs up there and it is not likely that both of them are bad.
Go get a ten dollar volt/ohm meter and check the continuity before you pull down the mast. There should be continuity between one of the posts to the other two and none between those two. The little multimeter is well worth the money for all sorts of jobs. If this checks out you the bulb is most likely not the culprit. On mine the contacts at the deck plug need to be cleaned often. Perhaps the fuse, the switch or the connection to either could be loose. There are two bulbs up there and it is not likely that both of them are bad.
Light up the sky
Oops! I hit the wrong button. You have a Perko dual light(two light bulbs) seperated by a wall between the bulbs which act either as steaming and/or anchoring. You indicated no lights which would tend to make me wonder about wiring first. I prefer using a 12 volt test light versus meter. Never gone wrong with it. First check the base on deck. Usually, ground will be the big hole while the other two holes are hot. If you get positive results or juice as I call it, Then you are fine. The next thing I would do is inspect the plug for it may be corroded(the rascal you plug into the deck with) and see if any wires are crossing and/or loose inside the plug. I bet this will be your problem. After that, you will have to drop the mast and check the light. IF both bulbs are damaged or shot sometimes like my brain can be shot, then you need to get two new festoon type bulbs to replace inside your perko light. Let me know how it goes. Crazy Dave
Oops! I hit the wrong button. You have a Perko dual light(two light bulbs) seperated by a wall between the bulbs which act either as steaming and/or anchoring. You indicated no lights which would tend to make me wonder about wiring first. I prefer using a 12 volt test light versus meter. Never gone wrong with it. First check the base on deck. Usually, ground will be the big hole while the other two holes are hot. If you get positive results or juice as I call it, Then you are fine. The next thing I would do is inspect the plug for it may be corroded(the rascal you plug into the deck with) and see if any wires are crossing and/or loose inside the plug. I bet this will be your problem. After that, you will have to drop the mast and check the light. IF both bulbs are damaged or shot sometimes like my brain can be shot, then you need to get two new festoon type bulbs to replace inside your perko light. Let me know how it goes. Crazy Dave
Test light...
... is OK when testing for current. It would not tell if there was an open circuit in the mast, as in a blown bulb. It also will not tell if you have a drop in current from a bad wire or connection. By disconnecting the battery and attaching its leads together you can also check the circuit going back through the fuse and switch. All this can be done without removing any fixtures or switch panels and gives a very good place to start the investigation. I use the test light to make a quick check for current. I would rather check the circuit before I brought the mast down or climbed up it to replace a bulb that I could tell was good while sitting on the deck drinking a beer.
... is OK when testing for current. It would not tell if there was an open circuit in the mast, as in a blown bulb. It also will not tell if you have a drop in current from a bad wire or connection. By disconnecting the battery and attaching its leads together you can also check the circuit going back through the fuse and switch. All this can be done without removing any fixtures or switch panels and gives a very good place to start the investigation. I use the test light to make a quick check for current. I would rather check the circuit before I brought the mast down or climbed up it to replace a bulb that I could tell was good while sitting on the deck drinking a beer.
Electrolytic Grease
If the problem is due to corrosion, a way to slow it down from reoccuring is to put some electrolytic grease in the socket. Put some in the sockets of the running lights too. Don't use this on halogen bulbs, or if you do, don't get any on the glass or it can be kissed good-by. This is available at automotive stores in the iginition parts section. This is what car manufacturers use on tail lights where there is a good possibility of moisture, and on wiring harness connections, especially under the car and in the engine compartment where there is a lot of water/moisture.
If the problem is due to corrosion, a way to slow it down from reoccuring is to put some electrolytic grease in the socket. Put some in the sockets of the running lights too. Don't use this on halogen bulbs, or if you do, don't get any on the glass or it can be kissed good-by. This is available at automotive stores in the iginition parts section. This is what car manufacturers use on tail lights where there is a good possibility of moisture, and on wiring harness connections, especially under the car and in the engine compartment where there is a lot of water/moisture.
Multimeter, Part II
Hi Bill, I am assuming you have checked the deck fitting and are getting 12 volts there. Rick is not quite correct regarding the multimeter measurements but he gives some good places to check. The cable from the mast light contains three wires as Dave mentions; ground and two current-carrying conductors. If you measure between ANY two of these, you should get continuity. If you measure between the gound and either current-carrying conductor, you will be measuring the resistance of one bulb. If you measure between the two current-carrying conductors you will read the combined (series) resistance of both bulbs. If you get an open circuit between any of these, it MAY indicate that the bulb is blown, but not necessarily. The cable is easy to snag and pull with a foot when it is screwed into the deck connector. I would first recommend that you take the male end apart and check to make sure all three wires are soundly connected. The connector uses very small screws so be careful when removing. If all connections look good, you will have to drop the mast. Hopefully you will just find a blown bulb or a slightly corroded socket. If not, the cable has severed inside the mast at some point and will require replacement. Mark Kissel Kittiwake/H240
Hi Bill, I am assuming you have checked the deck fitting and are getting 12 volts there. Rick is not quite correct regarding the multimeter measurements but he gives some good places to check. The cable from the mast light contains three wires as Dave mentions; ground and two current-carrying conductors. If you measure between ANY two of these, you should get continuity. If you measure between the gound and either current-carrying conductor, you will be measuring the resistance of one bulb. If you measure between the two current-carrying conductors you will read the combined (series) resistance of both bulbs. If you get an open circuit between any of these, it MAY indicate that the bulb is blown, but not necessarily. The cable is easy to snag and pull with a foot when it is screwed into the deck connector. I would first recommend that you take the male end apart and check to make sure all three wires are soundly connected. The connector uses very small screws so be careful when removing. If all connections look good, you will have to drop the mast. Hopefully you will just find a blown bulb or a slightly corroded socket. If not, the cable has severed inside the mast at some point and will require replacement. Mark Kissel Kittiwake/H240
Mark gets an A+
As both bulbs share the common ground wire you should get continuity between any two of the posts. That makes it alot easier to decide if the mast should come down or not. Next time I sit down at the computer with a cocktail I should read it twice.
As both bulbs share the common ground wire you should get continuity between any two of the posts. That makes it alot easier to decide if the mast should come down or not. Next time I sit down at the computer with a cocktail I should read it twice.
Thanks for the mastlight input...
Thanks Dave, Mark, Rick and John for the input regarding my mastlight problem. Very helpful. Our sailing season starts here in a few weeks and I will be making the repairs to light. Will let you all know what the problem was. Thanks again Bill W. s/v Renewal
Thanks Dave, Mark, Rick and John for the input regarding my mastlight problem. Very helpful. Our sailing season starts here in a few weeks and I will be making the repairs to light. Will let you all know what the problem was. Thanks again Bill W. s/v Renewal
Crushed Wire?
It may be possible to crush the wires to the light with the mast raising pole. You should be able to view a part of the wire by looking in that hole with a small flashlight. My antenna cable also comes down there so I have to be extra careful when stepping the mast. It's only a 10 minute job to step the mast for us and not a serious problem like the 'big boys'. Be sure to post the results for all of us. Ken S/V Wouff Hong
It may be possible to crush the wires to the light with the mast raising pole. You should be able to view a part of the wire by looking in that hole with a small flashlight. My antenna cable also comes down there so I have to be extra careful when stepping the mast. It's only a 10 minute job to step the mast for us and not a serious problem like the 'big boys'. Be sure to post the results for all of us. Ken S/V Wouff Hong
An aside to electrolytic grease
There are several good ideas about tracking down the fault in your mast light. But the electorlytic grease idea was new to me, may give it a try. The comment about tossing halogen lights if you get grease on them is an over reaction. I did a lot of theater lighting as an undergrad, mostly using 500w and 750w halogen lamps in our lights. The damage occurs when a contaminent such as sweat, dirt or grease, gets on the "glass" and because it does not transmit light as well, converts light to heat - a localized hotspot. We just wiped them very clean, and they worked fine. Jim Kolstoe h23 Kara's Boo
There are several good ideas about tracking down the fault in your mast light. But the electorlytic grease idea was new to me, may give it a try. The comment about tossing halogen lights if you get grease on them is an over reaction. I did a lot of theater lighting as an undergrad, mostly using 500w and 750w halogen lamps in our lights. The damage occurs when a contaminent such as sweat, dirt or grease, gets on the "glass" and because it does not transmit light as well, converts light to heat - a localized hotspot. We just wiped them very clean, and they worked fine. Jim Kolstoe h23 Kara's Boo
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