How to test a solenoid for a 18HP Vanguard?

Sean2202

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Greetings,

I was hoping that someone here could help me out. I have a Toro Greensmaster mower that uses a 18HP V-Twin vanguard engine that I believe may have a solenoid problem. I have tested these before in the past but I can not remember how to do so. I have looked in the service manual and there is no mention of how to test the solenoid. I was curious how to test in on the machine and how to test it off the machine as I have some sitting on the shelf that I do not know if they are any good. The battery test good under load and connections are good. How do I measure voltage drop?

Thanks for any help
Sean20191120_082943.jpg
 
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dougand3

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On the bench with 3 pole solenoid: 12v battery with 2 (+) leads. Hook one +12v lead to big pole #1. Hook battery ground to metal solenoid bracket. Test voltage at big pole #1.
Hook other +12v lead to little pole...should hear CLICK. Test voltage at big pole #2. Should be the same. Tells you the plate inside is being drawn by the magnetic field to connect 2 big poles.

Sometimes the plate gets burned and chewed up or corroded and contact between poles is not as strong.
 

Fish

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The solenoid is basically a switch that can handle a big load. It connects the battery cable to the starter to crank the engine. On your {4 pole} switch, voltage comes to the one small terminal when you turn the keyswitch to "crank" position, but on this solenoid, the other terminal must complete a connection to "ground", and both of these connections go through an assortment of switches to make a complete circuit to crank the engine.
 

Fish

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On a 3 pole solenoid, the ground is carried out through the base of the solenoid. So that style would be easier to run down.
 

Sean2202

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Thank you all for the replies, for the cost and piece of mind I just replaced the solenoid. Working 100% now. I bench tested one that was on the shelf and did hear a click but did not do a voltage drop test yet.
 
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