ZD 21 Solenoid problem

[KirkKing]

I’ve been having to start my old ZD 21 with a screwdriver for some time. So I ordered a new starter solenoid and installed it yesterday.
But when I went to connect the battery, the new solenoid immediately
made a “whirring” sound and the battery cable SPARKED.....not allowing me to reconnect the battery cable.
Soooo, I took the new solenoid off and put the old one back on so I could at least start the mower with a screwdriver again. NOPE.same thing happened with the old solenoid now....that Is, upon placing the battery cable back on I got the same “whirring” noise when the cable hit the post.....and sparks.

any help appreciated.

 

[Rivets]

Two things come to mind very quickly. When you install the solenoid you mixed up the wiring. On the solenoid you have either 3 or4 terminals. Let’s say you have 3 terminals, 2 large and one small. On one large terminal you will attach one large cable coming from the battery and one small wire going to the key switch. On the other large terminal you will attach the other large cable which goes to the starter. On the small terminal you will attach the small wire coming from the key switch or safety switch. If you have a 4 terminal solenoid you will hook everything the same, but the second small terminal will have a small wire going to ground.
If you have everything wired correctly, I suspect you have a bad key switch.

 

[Hammermechanicman]

You have it wired wrong. Check the cable from batt + to the starter solenoid. It goes on the large terminal farthest away from the starter body. You have the motor engaging but not the solenoid. If it is wired properly the solenoid is shorted but i doubt it with 2 solenoids. With the small wire disconnected from the solenoid does it do the same thing?

 

[KirkKing]

You have it wired wrong. Check the cable from batt + to the starter solenoid. It goes on the large terminal farthest away from the starter body. You have the motor engaging but not the solenoid. If it is wired properly the solenoid is shorted but i doubt it with 2 solenoids. With the small wire disconnected from the solenoid does it do the same thing?

Thanks for the reply, Hammer! But, it is wired like you mention. And when the new solenoid made this whirring sound I pulled the new one off and put the old solenoid back on so I could at least jump it with a screwdriver. But no......after putting the old solenoid back on and tried to place the battery cable on.....more sparks and more whirring. The solenoid Wires are on the far terminal just like when I pulled them off. Hmmm

 

[Rivets]

Sorry, I’m now very confused. Can you take a couple of pictures of how you have it wired.

 

[Hammermechanicman]

There should be a wire or strap coming out of the motor going to a large lug on the solenoid. The cable from battery + should go to the other large terminal on the solenoid. With nothing comnected to the small terminal the starter motor should not spin. No sparks. If you get the whirring noise which is the starter motor spinning but not engaging the flywheel you have somerhing wrong with the contacts in the solenoid.
When the solenoid engages and extends the starter drive it pushes the contacts closed between the large terminals to energize the motor.

 

[Rivets]

Sorry, I was thinking remote solenoid. If this is basically the starter you are talking about, only two wires should be connected to it. Large battery cable to the top terminal and small wire with spade connector on the side spade. This wire would be coming from the key switch. If you have a third wire it is probably a small wire which will supply current to the key switch and be connected to the same terminal and the battery cable. I know this may not be your exact starter, but shows the terminals. https://www.dbelectrical.com/produc...V5__jBx0BCwmKEAQYAyABEgKV9PD_BwE&gclsrc=aw.ds

 

[KirkKing]

There should be a wire or strap coming out of the motor going to a large lug on the solenoid. The cable from battery + should go to the other large terminal on the solenoid. With nothing comnected to the small terminal the starter motor should not spin. No sparks. If you get the whirring noise which is the starter motor spinning but not engaging the flywheel you have somerhing wrong with the contacts in the solenoid.
When the solenoid engages and extends the starter drive it pushes the contacts closed between the large terminals to energize the motor.

Hammer, yes....that strap from the starter is connected to the solenoid terminal that is closest to the starter. That’s where the cable was/is on the old solenoid I replaced. And that’s the same connection I made with the new solenoid. And as mentioned, I out the old solenoid back on.....or tried to. But got the sparks and whirrin. Damn, this is crazy. Maybe it has the virus. Hope not.....I’m too old to be around it?

 

[KirkKing]

Here Is pics of my old solenoid back on.

 

[Rivets]

In my opinion you have the starter wired correctly. If you cross the two large terminals, you will get sparks, as you are making a direct connection to spin the starter. The starter will not kick out because you will not energize the solenoid doing this. Have you tried to take a jump wire from the large battery terminal on the solenoid to the small spade terminal? This should energize the solenoid and speed the starter if both the solenoid and starter are good.