1972 65hp Johnson Starter Solenoid Issues

iamrudy

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Jun 18, 2008
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Hello everyone, I am having issues starting my 1972 65hp Johnson outboard. The problem first occured out on the lake about a mile from the boat ramp. After a lot of trouble shooting I think that my starter solenoid is bad. Here is some data I have come up with: the 12v constant is working correctly, the starter does kick over when applying 12v to it (using a jumper from the 12v constant), I get 12v on one of the small leads on the solenoid when the key is in crank position, the other small lead is grounded through the nutral saftey switch.

I am not a great mechanic, but I think this is everything the solenoid needs to work properly. Yet, the solenoid does not pass 12v to the lead going to the starter. I replaced the solenoid that was on it with a solenoid from a local automotive parts store (it is probably for an older ford) and it still doesn't work. Thinking that I may have bought one that was bad, I replaced it with one from a different automotive parts store. When I hooked it up I think I may have got the two small leads on the solenoid backwards. Could this have shorted out or damage the solenoid. Do I need to get a different solenoid more specific to this motor? Any help is appriciated.
 

iamrudy

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Jun 18, 2008
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Re: 1972 65hp Johnson Starter Solenoid Issues

I picked up a new solenoid at a nearby marine store. Everything works perfectly now. Thanks for the help. :)
 

jay_merrill

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Dec 5, 2007
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5,653
Re: 1972 65hp Johnson Starter Solenoid Issues

Most likely the reason why the Ford solenoid didn't work is that marine solenoids ground via one of the small posts, while an automotive solenoid grounds through its base. Trying to use an automotive solenoid for an outboard motor usually isn't a good idea. They also tend not to last very long in a marine environment.
 

iamrudy

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Jun 18, 2008
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Re: 1972 65hp Johnson Starter Solenoid Issues

You are correct about the grounding. Although, this one should have worked because it had all four post. I used the multimeter to determine that the top-most small posts was connected to the mounting bracket. So, whether you install it in a car using the mouting bracket to ground, or in a boat using the top-most small post, it should have worked. That's my thoughts anyway... evidently there's a little more to it.
 

iamrudy

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Jun 18, 2008
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Re: 1972 65hp Johnson Starter Solenoid Issues

Well, I am back again with the same issues. I went out to the lake yesterday all day. The seashark ran great up untill about 8pm. I ran out of gas on my primary tank, I thought, "No big deal I will just hook up the secondary tank." So, I shut the motor off and switched the tanks. When I try to start it back up I got nothing. Does anyone have any idea as to why I keep damaging the solenoid? The starter is dis-engaging correctly and crank time is never longer than 15 seconds.

One more thing... Now I can't recall for sure but I think the last time this happened to me I was really low, if not empty, on the primary gas tank. I wouldn't think the amount of gas I have would have anything to do with this. I think this was purely coincedense. Any ideas?
 

Xcusme

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Apr 21, 2003
Messages
2,888
Re: 1972 65hp Johnson Starter Solenoid Issues

Since you have a new solenoid, try looking down stream to the Neutral Safety Switch which should be in series with the solenoid. Check the switches' ground connection too. Remove the 'ground' wire (small terminal to safety switch from the solenoid) and use a jumper from that solenoid terminal to battery ground. If the starter works, the problem points down stream. Meter (Ohms) the wire to the safety switch (in Neutral gear), look for high resistance or an open wire. Double check that you're getting B+ to the solenoid terminal when you turn the ignition key too.
DO NOT bypass the neutral safety switch! Fix,repair,replace as necessary. Bypassing the switch is for testing only. It's dangerous to bypass it.
 

iamrudy

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Joined
Jun 18, 2008
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Re: 1972 65hp Johnson Starter Solenoid Issues

Thanks for the advice. I will give it a try in the next couple of days if I get some spare time.
I wrote up a wiring diagram for anyone that is interested...(click to make it bigger)
 

iamrudy

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Jun 18, 2008
Messages
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Re: 1972 65hp Johnson Starter Solenoid Issues

It seems that the neutral saftey switch was to blame this time around. :)
 
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