Ignition switch wiring

[fred1diver]

Hey everyone, I want to replace my ignition switch to where it was originally installed, in the cockpit ( easier to access the engine when solo) the switch has 7 connections on the back, I’m thinking the letters have a meaning to them, but it didn’t come with instructions so I don’t know what to connect, I hope someone can help me out

 

[senang]

It would help if you mentioned your engine type and year of manufacture. It will be easier to find the relevant documentation.

 

[fred1diver]

1972 Pearson 30, atomic 4 engine

 

[jssailem]

When confronted with such a mature boat the technique I use is to take a photo of the existing switch. Find a matching switch and wire it up like a twin.

This includes rewiring just match the colors and locations of the wires. Again photo the finished product and compare to the older image.

 

[JoeWhite]

My question would be, why are you replacing it. If it works and the contacts are good, you can draw a diagram and measure voltages of what happens when you turn the key. You can disconnect the wires and measure continuity of the terminals when you turn the key, then do the same with the new switch. This will help you figure out which wire should connect to which terminal.

 

[Stu Jackson]

the switch has 7 connections on the back,

That's unusual. Most have three or four: power, ground, I (ignition) and S (spring or switch). Perhaps gasoline engines need more.

You may want to do some "switch availability" research in addition to the fine field research ideas suggested so far. Check out Cole Hersee, they have a website.

 

[Kingjim91]

Here’s a typical wiring diagram for an A4 from Moyer Marine, your best source for parts and technical information.

https://www.moyermarineforum.com/forums/attachment.php?attachmentid=5&d=1112372128

 

[Richard19068]

Hey everyone, I want to replace my ignition switch to where it was originally installed, in the cockpit ( easier to access the engine when solo) the switch has 7 connections on the back, I’m thinking the letters have a meaning to them, but it didn’t come with instructions so I don’t know what to connect, I hope someone can help me out

Does the switch have 7 terminals? Or 7 wires attached to some lesser number of terminals?

What are the letters you are referring to? Can you give us a list?

 

[fred1diver]

Ok, so I figured which terminals to use, now I opened a can of worms with the wiring, I’m surprised the boat has not burned down, fixing the bad wires as we speak, now I’m trying to figure the ignition wiring, is it normal that the wire that comes out of the old switch is connected to the temp gauge? My multimeter tells me it’s the same wire, if that makes sense, all I need is a good positive lead abd everything will be in good shape

 

[fred1diver]

Ok, so, I wired it with the closest 12v to try it out and it works, just need to get a beefier 12v lead down there

 

[mikeracca]

Ok, so I figured which terminals to use, now I opened a can of worms with the wiring, I’m surprised the boat has not burned down, fixing the bad wires as we speak, now I’m trying to figure the ignition wiring, is it normal that the wire that comes out of the old switch is connected to the temp gauge? My multimeter tells me it’s the same wire, if that makes sense, all I need is a good positive lead abd everything will be in good shape

^^^ This is the exact reason I ended up ripping out every wire in my boat that wasn’t embedded in the fiberglass. My wiring was a mess and that is being polite to the previous owners. Over the weekend I finished up all the main wiring. I ended up replacing both the AC and DC sides. It wasn’t cheap or easy but I now know everything is new and good.

 

[mikeracca]

That's unusual. Most have three or four: power, ground, I (ignition) and S (spring or switch). Perhaps gasoline engines need more.

You may want to do some "switch availability" research in addition to the fine field research ideas suggested so far. Check out Cole Hersee, they have a website.

A gasoline engine only requires one more wire than a diesel. The wire to the coil is the extra wire needed. Depending on your ignition system you may need a ballast resistor to prevent damage to the points or ICM.