starter solenoid - testing & wiring diagram

casi77

Petty Officer 2nd Class
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need to know proper way to connect an starter solenoid (froma car, ie, ford solenoid) to johnson 50hp (wiring diagram if possible). & also to test each connection (S, I, from battery, to starter)

And how to test the safety or kill switch they call it, that is bolted on the block, one wire from the solenoid is hooked up to.

And how to wire it, without the safety/kill switch??

thanks
 

72SideWinderSS

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Re: starter solenoid - testing & wiring diagram

Car solenoids don't work on johnnyrudes.

I recomend that you invest in an OEM manual.

Regards,
jimmy
 

casi77

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Re: starter solenoid - testing & wiring diagram

could you tell me why it doesnt work then?

i already have the manuals.

72SideWinderSS said:
Car solenoids don't work on johnnyrudes.

I recomend that you invest in an OEM manual.

Regards,
jimmy
 

Silvertip

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Re: starter solenoid - testing & wiring diagram

The kill switch kills the engine when the switch is activated (contacts closed). So you can defeat it by simply disconnecting the wires. I have no idea why you'd want to do that however. As for the solenoid there is no mystery. There are two large posts on the solenoid. Ford or otherwise. The positive battery cable goes to one of them. The cable from the large post on the starter goes to the other one. If the solenoid has two small posts, one of them is ground and is grounded to the engine block. If there is only one small terminal, the case of the solenoid must be grounded to the block. The other one goes to the ignition switch "S": terminal. To test the system, have someone turn the key to START while you check for voltage on the small terminal. If there is voltage at that terminal, then check the large post going to the starter. If there is voltage there the solenoid is working and the starter or the short cable is bad or the connections are not tight. If there is no voltage at that terminal, check the other large terminal. The key does not have to be in the START position for this test. If there is no voltage present, the battery is dead or the cables are bad or loose, Voltage at that terminal but not at the other large terminal with the key in the start position indicates the solenoid is bad. On the first test (key in START, testing small terminal) if you get no voltage, there is whole host of possibilities ranging from dead battery, bad battery cables, bad ignition switch, bad harness, bad connection at harness connector on the key switch or at the engine.
 

Silvertip

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Re: starter solenoid - testing & wiring diagram

Forgot to add that the battery charging wire from the rectifier/regulator connects the large terminal on the solenoid on which the positive battery cable is connected.
 

F_R

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Re: starter solenoid - testing & wiring diagram

You don't say what year your 50 is, but you did say the safety switch is on the block. That's good enough.

:^As said, car solenoids don't work on those!

OMC solenoids have two small terminals. One is for the wire coming from the key switch. The other one goes to the safety switch. The safety switch grounds that terminal when it is safe to start the motor.

Ford solenoids look exactly the same but are different inside. On a Ford, the second small terminal goes to an ignition bypass resistor. A full 12 volt whallop is fed to that resistor when starting. If you try to use a Ford solenoid on an outboard, that full 12 volt whallop goes to the safety switch and destroys the safety switch almost immediately. No need to test it when you've done this, you've killed it.

OK, OK, yes you can use the Ford solenoid by just not connecting anything to the second small terminal and making sure the bracket is grounded. But then you don't have a safety switch in use and you can start the motor in gear at full throttle. Somebody could get killed! So don't do it - ever :%
 

F_R

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Re: starter solenoid - testing & wiring diagram

wiring1971-250hpgs.jpg
 

Silvertip

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Re: starter solenoid - testing & wiring diagram

Perhaps that's why he wants to eliminate the safety switch. The second terminal on a Ford solenoid doesn't "wallop" the ballast resistor on a car. It bypasses the resistor to provide the coil with full 12V for starting. Once running the ballast resistor drops the voltage to the coil. It would not have to be used on the outboard but you are correct in that the safety switch would be impacted if connected to that terminal.
 

F_R

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Re: starter solenoid - testing & wiring diagram

OK, wrong choice of words. It was awful early in the mornimg when I wrote that. But the correct idea. The "whallop" goes to the coil, bypassing the resistor, that is true. My point is that it feeds a full 12 volts directly from the battery (cable), which will burn up the safety switch if applied to it.
 

casi77

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Re: starter solenoid - testing & wiring diagram

ok thats great information! understand it a bit better.

Ok another question about this, at rest (without turning the key).. and checked with a volt meter for continuity between S, I, power to starter & ground.. what would be the results?

when i checked,
i saw that
there is continuity between ground and S, ground & I, ground & to starter, between S&I, between S&to starter, between I&to starter posts on the solenoid. this correct!?

another question.. what happens when we shut off the engine? ie. turn the key off ..engine shuts, but what triggers it and how can we test that mechanism if it is working or not.. what if the engine doesnt shut when key is turned.. where do we look first to resolve this?
 

ezeke

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Re: starter solenoid - testing & wiring diagram

Turning the key to "Off" closes the circuit between the two "M" connections: Black ground on one M, Black and Yellow kill wire on the other M.

The black and yellow kill wire leads to the power pack, so turning the switch to Off grounds the power pack so that it cannot fire.

If you disconnect the kill wire at the power pack, you will have no way to turn the running motor off except to choke it.

Don't put voltage on the kill wire.
 
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