1956 Johnson 30hp Solenoid Help

[rgballard]

Having trouble getting my starter solenoid wired. I feel stupid asking, but I have read a bunch of posts and I just really don't understand how to wire this thing.

First off I got the following starter solenoid (part #SW622 ). I have wired it per the the attached wiring diagram, however, I don't have a mercury switch so I am not really sure about that part. Also

I am confused about the drawing. It only shows a solenoid with three contacts, part sw622 has four. Though from reading I think the i terminal is irrelevant/obsolete for a simple set up.

So if I don't have a mercury switch where does the wire from the ignition switch go? Also does this solenoid have to be grounded, if so how?

I think I just need to talk this out, so I any conversation or info would be helpful, because I am so confused.

p.s. I generally don't have any trouble understanding circuits and am experienced with automotive and household electrical.

 

[1946Zephyr]

Re: 1956 Johnson 30hp Solenoid Help

Looking at the front of the solenoid, the left large post should connect to your battery and the right large post should connect to the starter. Now the smaller posts. The left should connect to the "S" terminal on your key switch and the right should go to a good ground on your motor. The mercury switch is there, to prevent you from starting the motor, if your throttle is set too high. Now, if you're an experienced boater, with a good level of common sense, you'll know to make sure your motor is out of gear before you hit the key switch and your throttle is set no higher than the start position. If you're good at being safe, then by all means, just connect that right, small post on your solenoid, to a good ground on the motor.

 

[rgballard]

Re: 1956 Johnson 30hp Solenoid Help

Thanks Zephyr. I must have tried different combinations last night and could not get it to work! Did what you said and it worked perfectly. Guess that is what I get for trying to wire stuff after a long day on the lake!

Thanks again!

 

[1946Zephyr]

Re: 1956 Johnson 30hp Solenoid Help

Cool deal. I need to wire a couple of my own boats up too. LOL

Just be careful about starting that bugger and make sure it's out of gear before you shut it down. That way, it will be out of gear when you start it back up. It probably wouldn't hurt to wire that mercury switch back up, but what I helped you with will get you out on the lake right now.

 

[HighTrim]

Re: 1956 Johnson 30hp Solenoid Help

I agree with Zephyr, you dont really need to worry so much about yourself, but mainly others that use the boat and do not fully understand any bypassing you may have done.

 

[rgballard]

Re: 1956 Johnson 30hp Solenoid Help

I guess I was confused about what you guys were saying about being in neutral, but I get it. I would assume most newer motors do not allow the starter solenoid to be engaged if the shifter position is not in neutral. Never really thought about that I guess I just take for granted that it has to be in neutral. Seems like this could be added easily with a little ingenuity, that way I would ever have to worry about it! Thanks for that added advice.

On a side note do all of these higher horse power older motors (i.e. my 30 hp 1956 Johnson) supposed to have these mercury switches off the factory floor? I know for a fact mine does not have one. I searched it all over (where it is supposed to be per my parts diagram). Would it be possible that someone removed it?

 

[HighTrim]

Re: 1956 Johnson 30hp Solenoid Help

They most definately all have them. Look inside your cowl where the wiring harness enters. There should be 4 wires, a ground attaching to the starter bracket, a POS attaching to the starter, a smaller red attaching to the choke solenoid, and a smaller black attaching to the mercury switch.

Right now you have your black lead coming from the start switch going to ground to allow the starter solenoid to function. The mercury switch normally does this, when it is level, in the correct starting position. The way you have it now it could start at full WOT RPMS. Potentially very dangerous.

The reason you were having trouble with the wiring is that you are going off of a 6 volt wiring diagram, when in fact you are using a 12 volt setup. Here is the 12 volt conversion wiring diagram to have it wired correctly. The old 6 volt solenoids are 3 post, as your diagram indicates, where as you now have a 12 volt solenoid. Makes it confusing right?

I actually just restored one of these mechanically for someone. I put it in the test tank last night, and could not get it to fire. Was not getting voltage across the solenoid. Finally tracked it down to my solder job had cracked at the mercury switch, not grounding the circuit causing it not to function.

This should clarify.

 

[rgballard]

Re: 1956 Johnson 30hp Solenoid Help

I see now, I also have this diagram, but it didn't make sense to me at first. Now it does. This motor didn't have a wiring harness so I had to make one from scratch. I just need to add the mercury switch and I think I will be all set.