On-Off-On Rocker Question - DPDT/SPST? Nav/Anchor wiring

big_chief

Seaman
Joined
Apr 5, 2010
Messages
65
I'm sure some form of this question has been asked many times... I'm stumped...

My Nav/Anchor switch failed afew weeks back (at sea... at night). I was able to rig the lights on 2 other switches to get back though.

When I went to purchase a new switch... I didnt quite think it through... I knew I needed an Illum-On-Off-On... but didnt consider the type (DPDT/SPST). When I went to install it, I realized I purchased a DPDT (7 pin) and the old was a (4-pin), I assume is SPST? It was using a diode...

Should I just be replacing this with a like switch... or change the crimps to use the DPDT? Advantages/Disadvanges? I got a Seachoice (12991) but didnt even see a SPST 4-pin from them? Is one more common than the other? Brands?

Thanks for your insights...
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
No problem. Just wire up one side of the switch instead of all the terminals. You basically have two SPDT center off toggle switches in one. So just wire it like the old switch and you will be okay...
 

big_chief

Seaman
Joined
Apr 5, 2010
Messages
65
Thats what I was thinking... but for some reason it wasnt working? I hate to think the switch is bad...

I was using 7 as the ground (the odd pin). My first shot was using 2 as + and 1 and 3 as the lights. (similar to the original setup). But it didnt work. Essentially, I was using 1 side of the switch in this setup. This was the 3 pin side with the #7 on the other side. When I would test for power on any of the pins, 1, 3, 4, 6, I got nothing.

Then I tried using the other side (the 4 pin side). I used 7 again as ground. And used 5 as +. When I did this, I was able to test for power on 4 and 6. But when I wired a light to either, the power went away? Am I missing something?

I know the lights work, because I can turn them on with 12v without the switch.

Thanks..
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
The ground is only used for the switch's light.

8220_8286.jpg
 

ssobol

Chief Petty Officer
Joined
Sep 3, 2010
Messages
503
Make sure the diode is right way around.

I don't remember the numbers, but the center tab should be +v input. The lights connect to the end tabs. The grounds from the lights connect to your ground point and shouldn't come back to the switch. There will be one ground pin on the switch that is for the internal lights and that should also go to your ground point.

See this picture;

https://www.bakesonline.com/images/MediaLibrary/rkrswitchdpdt.jpg
 

big_chief

Seaman
Joined
Apr 5, 2010
Messages
65
I solved the problem... sort of.

Thanks for all the replies. I enjoy the forums when Ive scratched out to much hair and need a beer... I also like to see it when people post the final results, so here I am.

So had another shot today and still nothing... started at step 1 and tested 12v on the lead, with a meter, yet no action on the switch. I have an empty accy switch wired to 12v, which I have been using to test the lights to rule them out. This time, I used the 12v wire from that switch to my on/off/on and IT WORKED.

I traced the original wire back to the bus and swaped the pin to an empty slot and it worked now.

Result... something was bad in the bus bar. What I can't figure is why it gets 12v on a meter... but wont operate the light... Im guessing it was just a matter of current?

My last question... is it common for bus bars to fail like this? It looks in decent shape, never gets wet, etc... I assume OEM, boat is 2001. It got dark, so I had to wrap up. I plan to check all my wires for corrosion and possibly swap the bus.

At least I know what the issue is now... Thanks for your insights.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Sounds odd that the 12 volt positive buss bar was the problem. Something surely isn't right there. Maybe you can investigate further with daylight and let us know what you've found. Sounds like a corrosion issue to me...
 

Grandad

Lieutenant Commander
Joined
Jun 7, 2011
Messages
1,504
I solved the problem... sort of.

Thanks for all the replies. I enjoy the forums when Ive scratched out to much hair and need a beer... I also like to see it when people post the final results, so here I am.

So had another shot today and still nothing... started at step 1 and tested 12v on the lead, with a meter, yet no action on the switch. I have an empty accy switch wired to 12v, which I have been using to test the lights to rule them out. This time, I used the 12v wire from that switch to my on/off/on and IT WORKED.

I traced the original wire back to the bus and swaped the pin to an empty slot and it worked now.

Result... something was bad in the bus bar. What I can't figure is why it gets 12v on a meter... but wont operate the light... Im guessing it was just a matter of current?

My last question... is it common for bus bars to fail like this? It looks in decent shape, never gets wet, etc... I assume OEM, boat is 2001. It got dark, so I had to wrap up. I plan to check all my wires for corrosion and possibly swap the bus.

At least I know what the issue is now... Thanks for your insights.

When there is a poor connection, such as what you apparently had at the bus bar, voltage may appear to be present according to a meter, particularly a digital meter. Such meters draw very little current to operate. When you apply a load such as your lights, the poor connection at the bus bar won't allow sufficient current to flow through this high resistive poor connection. The voltage "drops" substantially across the resistance and your meter registers this loss in voltage. It's the same for a "dead" battery. With no load connected, a voltmeter may indicate 12 volts or more, but as soon as any load is applied, the voltage drops right off.

A failure at a bus bar can be caused by a loose termination or corrosion just the same as a failure at any other electrical connection. - Grandad
 
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