Motor won't start, Neutral safety switch broken? Need wiring diagram

[Tonygotskilz]

Hello, i previously had trouble starting my 1972 50hp Johnson Hydro-electric shift and i looked in the faq but i'm still not sure what the problem is.... <br /><br />Ok My engine ran fine 2 weeks ago, but one day i started it up and got the over heat horn (Started before motor even started, horn would sound when i turned key, then motor started just fine... but horn kept going) so i shut it down and 2 days later i tried to fire it up again and NOTHING... Batteries fine, i thought it was the starter relay, replaced it still wont' start... I measured voltage at the relay and there was no change (when checking top wire and bottom wire on relay while turning the key... the voltage was around 12.4 constant before turning key after and during) when you try to crank motor... No click from relay and no motion from the starter...<br /><br />Anyone have any clue whats going on? Weird thing is when you turn they key to on, or start you can hit the toggle switch for the choke, and the choke moves, so i know the motors getting power, but it doesn't want to turn over, its in neutal when i try all of this but i'm thinking that maybe somehow it doesn't know its in neutal and hte neutral start switch is giving me the trouble... Can i disable it and try to start? I opened the control box and it looked like all the wiring was in tact but i have no clue what i'm looking for... Any help would be greatly appreciated, i'm just trying to get this working so i can sell it and the boat its attached to...

 

[Paul Moir]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

On the two little posts on the starter's solenoid, if when you crank the engine they're both 12v then the neutral switch isn't switching. If they're both 0v then it's the ignition switch that's bum, and if one is 0 and the other is 12, it's neither and you should here a good click from the solenoid, if it works.<br />Basically, the ignition switch provides +12v to one of the small posts, and the neutral switch provides a ground (-) to the other.<br /><br />Good luck!

 

[SCO]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

The overheat horn, if was cold when horn went off, indicates a short or bad temp sensor. The no start cause could be a corroded bat terminals, corroded wires, things that allow low current apps like the solonoid, but cant pass big starting currents... It is all relatively simple, but you have to get schematics and manuals and learn your engine. If purpose is to sell you wont be properly motivated. I recommend that you take it to a shop and ask for an evaluation to fix it, and how much the evaluation will cost. Good luck.

 

[R.Johnson]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

You say you want to get it running so you can sell it, have you given any thought to "As Is", or " do it yourself special" ?

 

[Tonygotskilz]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

I won't get what its worth if i sell as it, especially since the problem is something small and silly i'm almost definite. Like i said its measuring 12 volts when the key is turned on the 2 relay posts... So i'm pretty sure the its the neutral switch, i just have no clue how to fix it.....

 

[Xcusme]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

Tony,<br /><br />If you measure the two wires at the neutral safety switch and one is 12VDC , the switch is not closing (assuming you are in neutral) and providing a ground connection to complete the solenoid circuit. The other wire of the neutral safety switch should be connected to a good ground connection. <br /><br />Try this, turn ignition key off.<br />Find the wire at the neutral safety switch that had 12vdc when you turned the key to start the motor, temporarily connect this wire to ground.<br /><br />Turn key to start.<br />If motor cranks, the neutral safety switch is defective.<br /><br />Or, <br /><br />The switch is not being actuated by the linkage when the shift controls are in the neutral position. <br /><br />Or,<br /><br />The ground wire of the neutral safety switch is open or has a bad connection to ground.

 

[Tonygotskilz]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

Ok maybe i'm confused as to exactly what and where the neutral safety switch is... Inside the control box (shifter and keybox) theres a little black box all the way to the frontside of the bow away from the key... There are 5 wires running to it, one purple two white, on green and one blue... I thought that was the neutral safety switch. I think this because its the only part inside the box thats connected to the shifter... It has a little nub on top of it that has a spring under. It turns when you move the shifter.... Problem is, the nub that goes on top is broken.... So i'm thinking the neutral safety switch (if thats it) has no way of knowning its in neutral.... If i'm correct what i want to do is figure out what wires i need to cut and splice to fool the box into thinking its in neutral thus bypassing this broken switch... Is that a posibility and if so does anyone have the wiring diagram or know which wires i need to connect to make it think its in neutral... Since theres 5 wires going to it theres about 120 possibilities so without a wiring diagram i'll never figure it out.... I don't understand your post cause you say theres only 2 wires runnin to the neutral safety switch? Or are you saying to cut into them and figure out which one is ground and which one is power and splice those two? I'm confused... And if its that simply why do 5 wires go to it? Thanx again, i think i'm finally getting somewhere since i believe i've isolated the problem to this switch... If nobody knows what i'm talking about i'll take some digi pics tomorrow ....

 

[rickdb1boat]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

The white wires are the ones you want to splice IF that in fact is the neutral safety switch in the box. There may also be a safety switch in the circuit. Look for it by the shift linkage in the motor compartment. If you find one there, it should have the white wire going to it. Wait for others to chime in before you go to cutting. The diagram I have is for your year, but not all the colors jive. Yours may be different.<br /><br />Blue-to shift selonoid(Neutral) <br />Green- to shift selonoid(reverse)<br />White to starter selonoid and then to safety switch in motor compartment.

 

[Hooty]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

Does your engine have tilt & trim? If it does, is it controlled from the remote control? What I'm getting at is the blue and green wires might be the tilt and trim control wires. The neutral switch should only have two (2) wires.<br /><br />c/6<br />Hooty

 

[Tonygotskilz]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

I knew this wouldn't be easy... Nope my motor doesn't have tilt/trim... all the wires go into the black box on top of the box is a little thing that swivels, it is obviously made to fit into a grove that is cut out of the bottom of shift lever (you can only see this with case open) the bottom of the shift lever is circular and towards the front (towards the place where the black box with the swiveling thing is sticking out) is a notch or grove. It looks as if when the motor is in neutral the grove lines up with the part that extends from the black box this is why i think its the neutral safety switch...There is absoltely nothing else touching the shift lever in there except for the shift cable on the other side of the level.... The case is the original case for the motor i believe cause it says Johnson hydro-electric shift on the outside (as does the motor) .... So tomorrow i'm going to assume its the two white wires, and go splicing away ( i can always splce them back if i have to so it should not be a problem.... Is there special voltage i should look for or continuity to make sure i'm splicing the right wires...? I'm really confused by this...<br /><br />Blue-to shift selonoid(Neutral) <br />Green- to shift selonoid(reverse)<br />White to starter selonoid and then to safety switch in motor compartment. <br /><br />for one i thought the safety switch was in the shift level box (where the key goes) not "in the motor compartment". And secondly Shouldn't it just be a switch... like if two wires connect...the switch thinks the boats in neutral so that when you turn the key it starts...whereas if it doesn't think its in neutral it won't allow the motor to start? If thats the case then whats up with the blue to shift and green to shift explaination? the keybox shouldn't have any effect on whether your in reverse or forward that should be controlled by the shift cable and by the solonids in the lower unit... I'm just getting more and more confused thanx for all the help though

 

[Hooty]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

"Hydro-Electric Shift"<br />If I'd been paying attention, I would have seen that. <br />I don't have a wiring diagram so I can't help ya with that. What I'd do is start at the starter solenoid and trace the wires back towards the control and try to find the neutral switch. Wish I could be more help.<br /><br />c/6<br />Hooty

 

[rickdb1boat]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

Tony<br />Your motor shifts electrically, as opposed to mechanically shifted motors. There is no shift cable, only selonoids that are controlled from the shift selector. When you shift to Neutral, power is applied to the neutral shift selonoid from the green wire in the control unit, which places the motor in neutral. When you shift to reverse, power is applied to the reverse shift selonoid from the blue wire in the control box. When the motor is off, it is in the forward gear. When you go to start the motor and turn the key with the shift lever in the neutral position, it switches to neutral so it can start. It will only do this when the key is turned and power is applied to the shift selonoid in the lower unit. I know it confusing, but that's the way those hydro units are. As Hooty suggested, start at the starter selonoid terminal(Should be a smaller white wire) and trace it back to the safety switch.

 

[ledgefinder]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

The switch on motor keeps you from starting it with the throttle above idle. There's a second one in the control box that only allows starting when you're in neutral.<br /><br />If I remember right, the one on the motor grounds the white wire at low throttle positions, completing the circuit so the starter solenoid can work. Those switches go (break or get out of adjustment) all the time.<br /><br />At this point you have enough wiring issues that you really need to find a wiring diagram, sit down & figure the thing out.

 

[R.Johnson]

Re: Motor won't start, Neutral safety switch broken? Need wiring diagram

If that switch in the control box has the arm broken, you will have to replace it for the shift to work. Have you checked the main fuse on the engine harness under the hood. It is a red pull-apart connector, the fuse is only about 5/8 in. long.