Neutral start safety switch test.

[artificialreef]

Hello folks. i am not getting spark from my coil to the dizzy. I tried a new coil and a new ignition switch, still nothing. I am also getting intermitten not turning over which is starting make me think Neutral start safety switch. This is on a 1983 470 and has the 4 inch long metal knife looking like actuator. Not the newer plunger type.
1. Could someone please explain the test procedure? I know how to use a multimeter. I understand you can jump a switch but wouldnt (please explain how to do that)that just allow it to turn over? Wouldnt the ground still be in the circuit? I want to see spark at the coil too.
2. Don mentioned most of the trouble is with the newer plunger type. If mine is in fact bad is there a specific plunger type to stay away from. I dont want to put garbage back into my boat.
Thank you for sharing your knowledge.

 

[Haut Medoc]

Re: Neutral start safety switch test.

In this scenario, I would start with testing the ignition switch.......
The neutral safety switch interrupts the yellow/red wire that goes to the solenoid......
It has nothing to do with the distributer.....

 

[stonyloam]

Re: Neutral start safety switch test.

If your engine turns over at all it is not the neutral safety switch. I think there may be some confusion here. Are you talking about the neutral safety switch in the control handle (disables the start circuit), or the shift interrupt switch on the engine (that interrupts the ignition circuit when you shift)? Two very different things.

 

[Haut Medoc]

Re: Neutral start safety switch test.

If your engine turns over at all it is not the neutral safety switch. I think there may be some confusion here. Are you talking about the neutral safety switch in the control handle (disables the start circuit), or the shift interrupt switch on the engine (that interrupts the ignition circuit when you shift)? Two very different things.

I agree......
The reason I suggested testing the ignition switch is because it is the source of power for both systems....
Intermittant suggests a faulty switch or connection.......
Bypassing the neutral safety switch & disconnecting the shift interrupt switch to see if it will start would be a quick & easy test.....

 

[artificialreef]

Re: Neutral start safety switch test.

I am trouble shooting the roller switch connected to the motor that interrupts the motor when taken in and out of gear. I put an ohm meter on the port motor (this one works)and at rest it reads 11ohms. In gear its 0 ohms shorted. I tested the starboard (the one with intermittent turning over and no spark) and it shows shorted in gear or out of gear. I think i may have answered my own question but dont want to keep throwing parts at it like an amateur. Allready tried new coil and ignition (key).

 

[artificialreef]

Re: Neutral start safety switch test.

To me 11ohms is still a short. Maybe the autoranging feature on my multimeter is not showing kohms.

 

[Haut Medoc]

Re: Neutral start safety switch test.

Now that we have identified that you are working on the shift interrupt, I would disconnect the switch & see if the engine will run.....
What voltage reading do you get at the + terminal of the coil with the ignition switch in the 'run' position....
If you changed the ign. switch, you may have a problem with the neutral safety switch, but that is not related to your 'no spark' problem....

 

[Haut Medoc]

Re: Neutral start safety switch test.

The switch at rest should read infinity.....(No continuity)

 

[stonyloam]

Re: Neutral start safety switch test.

OK, shift interrupter switch. Just remove the green/white wire from the switch and give it a try. Read this too: http://forums.iboats.com/showthread.php?p=1930449#post1930449 Make sure you have voltage to the coil with key on (about 7-8 volts if you have resistance wire in place).

 

[artificialreef]

Re: Neutral start safety switch test.

Sweet, i think i figured it out. After i determined the shift interrupter was working properly i ohmed out the wires leaving there. They were shorted. That led back to the coil. The black wire on the neg side of the coil was dead shorted to grd. I traced it to the dizzy where, when i changed my points i put the connector on upside down where it was touching the base plate of the dizzy making a circuit to ground. I havent turned it over yet but the circuit is ohming out the way the other motor does. No more short on the interrupter switch until i acitvate it. Thank you for your patience and help friends. i will report back when i get it to run. Knowing how to use an ohm meter is pretty handy. Haveing a running motor sitting next to you to compare to is priceless.

 

[achris]

Re: Neutral start safety switch test.

Glad to hear you have it sussed out, but the original post should have started with .... "I have just replaced the points in my 1983 470 and now I have no spark and it won't start..." That would have given us all the information... Just saying....

For future reference there are 2 or 3 switches (depending on the year) involved in the starting and ignition circuits.

1. Neutral safety switch. This switch lives in the control box and is normally closed when the control is in neutral. It disable the STARTER circuit. If the control is in gear (forward or reverse) the engine will not crank.

2. Shift interrupt switch. This is a normally open switch that lives on the shift plate at the engine end. It's job is to short the '-' side of the coil to ground as the drive is moved OUT of gear, never while going into gear.

3. Ignition kill switch. (may not be on all installations) This switch will be up near the helmsman somewhere. It usually has a lanyard attached, which the helmsman should secure to himself. If the helmsman moves farther away from the switch than the lanyard would allow it opens the switch and removes power from the '+' side of the coil.

All these switches are completely independent of each other....

Chris.........