neutral safety switch operation

archcycle

Chief Petty Officer
Joined
Sep 21, 2009
Messages
647
1990 johnson 140

When the neutral safety switch is engaged does it stop the motor from running (kill a running motor) or does it just ground out the keyswitch from sending voltage to the starter solenoid?
 

Joe Reeves

Supreme Mariner
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Feb 24, 2002
Messages
13,262
Re: neutral safety switch operation

It has no effect on the engine's running performance. When engaged, it simply opens the circuit leading to the starter solenoid which effectively stops the key operation from engaging the electric starter solenoid.
 

archcycle

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Sep 21, 2009
Messages
647
Re: neutral safety switch operation

About two years ago, one OMC keyswitch (summer 2011) and one motor ago (January 2010), I had an intermittent problem where I would be out on the water and and occasionally I'd turn the key and nothing at all would happen. Banging on the control box would fix it sometimes and otherwise just waiting 15 minutes or so would fix it. One day it magically fixed and never happened again. At the time that was good enough for me.

This weekend it happened again. Banged around on the control box, ran it F and R, put it in neutral and ran it up and down a bit, but still nothing. I turned the keyswitch to on and rope started it on the first pull. That was pretty awesome and really relieving considering I'd never bothered to try it before :). After a minute I decided to do some troubleshooting and shut it off. The key fired it right up. We started to leave when I couldn't resist trying it again. Nothing happened when I turned the key so it was back to the rope and we went home. Didn't have a multimeter on me but after enough of these issues I'm going to buy a second multimeter today and it's going to live on the boat.

Anyway, I wanted to get that issue cleared up before I went out and stood in the cold rain checking the keyswitch. I'm assuming it's some kind of potentiometer with a plunger or a paddle that could get sticky? I can see where the wires go into the control box but don't think my box is a lot like the one in this manual. The boat came with this box and a 1980 90hp but who knows if the box was even from that motor.
 

F_R

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Jul 7, 2006
Messages
28,195
Re: neutral safety switch operation

What motor do you have now? Some have a safety switch on the motor. But anyway, since we don't know what control you have it is hard to say what's in there. Almost always the neutral start switch is a simple push button switch operated by the shifter. It could be bad. If it is bad, it won't keep the motor from running, just keep you from cranking it with the starter---you did say it fired right up by rope starting it.

The parts book doesn't show a 1980 90hp. The 1980 100hp control does show a neutral switch in the control.
 

Chris1956

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Joined
Mar 25, 2004
Messages
27,036
Re: neutral safety switch operation

Arch, Sometimes the neutral switch wears a bit. If it doesn't work, turn and hold the key in the start position. Now wiggle the throttle handle front to back and see if you hear the starter. That is better than rope starting that big V4....
 

will62

Petty Officer 2nd Class
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Nov 25, 2011
Messages
103
Re: neutral safety switch operation

I don't believe there was an '80 90hp, but at any rate, that remote is probably very similar to my '79. Your problem could also be a key switch that is starting to fail, and not making contact between the B and S terminals on the switch. A continuity check at the plug wouldn't tell you which one (key or neutral) was causing the problem, so you'd probably have to open the remote to locate the problem. If you do remove the neutral switch, be careful with the detent spring just below it (very strong spring).

Since the problem is intermittent, it could be difficult to isolate. The next time that it happens, try moving your lever forward and reverse a few times to allow the neutral switch to open and close, then try to start it. If that doesn't work, jiggle your key a bit as you are turning it. If either of those work, it'll help you narrow down which one is causing the problem. If neither work, and you don't want to pull start the motor, just jump 12v from the large battery terminal to the small ignition terminal on the solenoid (key on).

I'm including a diagram and pic that will hopefully help you in locating the problem.
Remote wiring 3.jpg
Remote neutral safety switch.jpg

Edit: Didn't see F_R's and Chris1956's posts until after posting mine. Listen to what they say.
 

archcycle

Chief Petty Officer
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Sep 21, 2009
Messages
647
Re: neutral safety switch operation

The old motor was a 1983 90hp model J90TLCTE, my mistake earlier.

Will try all of those suggestions next time the issue resurfaces. If some cursory tests this evening don't turn anything up it might be best to just wait for it to happen and then troubleshoot since I know I can get it started when/if it crops back up. I like to think of myself as a reformed parts thrower and the temptation might be too great if i start testing things and there is no symptom ;).

I do have a small metal fish scale onboard that I've used to jump the solenoid a few times. A long time ago when my wife raised some concerns about a spark when I jumped it I told her it was a 'boat starter' and not to worry as it was meant for doing this; she was relieved to hear that. When I got back and told her about this problem she asked why I didn't just use the boat starter. I was confused. She described the tool she was referring to and it all came back. Instead of laughing as hard as I did, she got MAD at me for lying about the rusty old fish scale/'boat starter'! Apparently she'd taken solace in the fact that if the boat broke down out in the Gulf of Mexico that she wouldn't be stranded since I could always just use the boat starter to get it running but now that feeling of safety is shattered lol! A word of caution to all men to allow their tools to remain mysterious to the opposite sex.

As for that solenoid though, I did try that, and got nothing. I've personally never experienced an intermittent solenoid (works or dead) so when it fired up with the key after the pull start I wrote the solenoid off as an issue. That is a pretty invaluable spare to have on hand with the rest of my broken-down-in-the-gulf-dry-box-of-spares, so I'll make an exception to the no parts throwing rule and pick one up ($20 why not..) today and justify it as a spare. That way I can thoroughly test the solenoid with the boat's new live-aboard multimeter next time this occurs and swap it out if that's it.
 

rothfm

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Joined
Sep 26, 2006
Messages
913
Re: neutral safety switch operation

Thanks, I got a good laugh about the "boat starter" thanks funny....Yep, point taken!!
 

archcycle

Chief Petty Officer
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Sep 21, 2009
Messages
647
Re: neutral safety switch operation

For now I have no idea if it was the neutral safety switch but it is working. Though of course it's always working fine until it isn't and last time I didn't do anything and this symptom went away on its own. At least the boat has its own multimeter in the dry box now (and a print of that keyswitch wiring in case I'm out of cellular data range) so if I forget the tool bag there will still be one of those. Knowing that it will pull start without a fight sort of makes me want it to show up again because I don't trust that it's addressed.

Replaced the starter solenoid, putting the one I took off into the bag of onboard spares
Replaced the connectors to the solenoid with far more trustworthy ones
Pulled all of the engine grounds and dremel brushed the surfaces, replaced several connectors, coated everything in dielectric grease, reattached and painted the connections with liquid electrical tape
Pulled the positive into the starter and dremel brushed the corrosion off of the connectors

So if it was solenoid or wiring then it's fixed, and if it was something else like the neutral safety switch then there will be No question about this whole area of the starting circuit when it comes time to troubleshoot.
 

archcycle

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Sep 21, 2009
Messages
647
Re: neutral safety switch operation

The problem resurfaced. Unfortunately there wasn't much time for real troubleshooting, we had to get home, but I can mark a few things off.

Held the key on start and moved the controls around a lot and got nothing. Banged on the box, ran the controls through their full range, nothing happened.

Bridged the solenoid and nothing happened. This one was really surprising. I know the connections are good on this brand new solenoid because I just replaced the ring terminals to the solenoid and cleaned the grounds etc.

It is too bad it didn't happen earlier in the day, I had my boat tools onboard and even my manual from working on something else but there just wasn't 5 minutes to spare to do a few checks. It was terrible timing. I rope started it on the first pull and we got on our way. Hopefully the issue hasn't correct its self again by the time I get home this evening.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: neutral safety switch operation

You jumpered the starter primary winding to the battery capel and the starter didn't spin? Older Johnnyrude motors had the neutral switch on the ground side of the solenoid primary, but I didn't think that was practice on your motor.
 

archcycle

Chief Petty Officer
Joined
Sep 21, 2009
Messages
647
Re: neutral safety switch operation

Clarification I bypassed the starter switch by jumping the main hot to the switched hot on the solenoid. Did not bypass the solenoid.
 

archcycle

Chief Petty Officer
Joined
Sep 21, 2009
Messages
647
Re: neutral safety switch operation

Here's what I got done last night:

Step 1 in the manual was to disconnect the solenoid ground ring terminal from the block and put a voltmeter between it and the block and turn the key to Run, and if it gets 12v then move on. It showed 1.7v when OFF, and then showed 11.7v when ON and no change still 11.7v at RUN, and after shutting it off again it would hover around 2.5v for a while before going back to 1.7v. Checked the battery directly and it had 12.5v. It seems to me I shouldn't have any voltage at OFF but the manual didn't mention anything about that.

Next I bypassed the solenoid altogether with a tiny jumper wire from the hot at the solenoid's in to the starter's in and the tiny wire passed enough voltage to spin the bendix without raising it. Removed the starter in bolts and connector and cleaned their already pretty good looking surfaces up with a drill brush as long as I was in there.

Then I pulled the new Sierra solenoid off to test it. Hooked up + and - directly from the battery and got nothing. So I got the old solenoid which I'd replaced for good measure last time and got a crisp CLACK. Back to the brand new Sierra and still nothing. Installed the old solenoid and found my receipt for the Sierra..

Turned the key and still nothing.

Hooked up the voltmeter between the ground ring and the block and still showed 1.7v at Off.

Swapped my optima blue top out for my interstate marine cranking just to be sure it wasn't a battery issue but still nothing.

Then it started to get dark and the mosquitoes showed up in force and I had to call it a night. Hooked up the charger overnight, again just to be sure it wasn't a battery issue, and it didn't crank this morning.

I guess this evening will be keyswitch tests.
 
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