I have Deere 125a that won't start

[Brian B]

I could jump the solenoid, so I thought that was the problem, but after replacing it, it still won't start. Replaced the 20A fuse just in case. The battery is fully charged. Did some voltage testing and one side of the solenoid is energized but not the other.

 

[Doc]

Is there a way to test the solenoid to ensure it is a good one. Sounds like even the new one might be bad. To often someone returns one and the store doubts the customer and sells it again .....

 

[bczoom]

When you jumped the solenoid, you're talking about the one on the side of the starter, right?

On many pieces of equipment the size of your tractor, there's a second solenoid. It's between the battery and the solenoid that's on the starter.
In my experience, they're what goes bad.
Confirm, but this should be the one for your tractor.

Amazon.com

 

[bczoom]

Hey @Brian B
You posted and never came back. What's the resolution?

 

[DieselDustRay]

I could jump the solenoid, so I thought that was the problem, but after replacing it, it still won't start. Replaced the 20A fuse just in case. The battery is fully charged. Did some voltage testing and one side of the solenoid is energized but not the other.

If you're getting power to one side of the solenoid but not the other when turning the key, it might still be a safety switch issue—seat switch, brake/clutch switch, or even the PTO switch can all interrupt the starter circuit.
Check next:
Make sure all safety switches are engaged (seat occupied, brake pressed, PTO off).
Try bypassing the seat or brake switch temporarily (with a jumper wire) to see if the starter engages.
Double-check your ground connections, too—clean and tight.
Also, test if you're getting voltage to the small wire on the solenoid when turning the key. If not, that confirms the issue is upstream in the safety circuit or ignition switch.