New Holland TS125a Won't Turn Over

[SLHADLE]

My son used my New Holland TS125a for some field work and forgot to turn the key completely off when he parked it. He left the key in the "accessory" position. (It's very easy to do on this tractor.) Anyway, I went to start it 2 days later and, of course, the battery was dead. I attempted to jump it with no success. So, I charged the battery over night and tried again.
This time the dash lights came on but nothing from the starter. I made sure all gear shifters we're in neutral, the shuttle shifter was in neutral, park brake set and clutch fully depressed. Again, nothing from the starter.
I found the ignition relay was bad and replaced it. This time, when I tried to start it, there was nothing. Not even dash lights.
I found a blown fuse, but that still didn't fix the problem. I did find a bad connection at the starter and repaired that and also cleaned and tightened the battery cables. But still no luck.
Yesterday, I checked the clutch switch. It checked good with my meter. I even tried shorting the starter terminals, the starter engaged and spun with plenty of power.
The starter relay is good as well.
I am at a complete loss for what I am missing. If you have any suggestions, I am open to any and all ideas.

Sorry this is such a long post.

 

[Jerry/MT]

My son used my New Holland TS125a for some field work and forgot to turn the key completely off when he parked it. He left the key in the "accessory" position. (It's very easy to do on this tractor.) Anyway, I went to start it 2 days later and, of course, the battery was dead. I attempted to jump it with no success. So, I charged the battery over night and tried again.
This time the dash lights came on but nothing from the starter. I made sure all gear shifters we're in neutral, the shuttle shifter was in neutral, park brake set and clutch fully depressed. Again, nothing from the starter.
I found the ignition relay was bad and replaced it. This time, when I tried to start it, there was nothing. Not even dash lights.
I found a blown fuse, but that still didn't fix the problem. I did find a bad connection at the starter and repaired that and also cleaned and tightened the battery cables. But still no luck.
Yesterday, I checked the clutch switch. It checked good with my meter. I even tried shorting the starter terminals, the starter engaged and spun with plenty of power.
The starter relay is good as well.
I am at a complete loss for what I am missing. If you have any suggestions, I am open to any and all ideas.

Sorry this is such a long post.

Did you make sure the PTO lever was in the OFF position?

 

[SLHADLE]

Did you make sure the PTO lever was in the OFF position?

Several times.

 

[SLHADLE]

How would I test the ignition switch?

 

[TractorTech]

Does the starter relay click? Do you have 12v on the solenoid wire when swutch is turned to start?
Are your battery clamp to cable end clean from acid?

 

[SLHADLE]

It's been a while since I posted. So, here is an update.
I found the transmission shuttle switch was bad. After replacing it, the starter now clicks once when I try to start the tractor.
I removed the starter and tested it on the bench. When I connect it to a battery it engages and spins. When I put it back in the tractor, it only clicks once and does not spin.
I verified the engine was not locked up by spinning the harmonic balancer on the front.
Is it possible that my starter is just that week?
I tried jumping it from my truck as well. Same issue.
In short, I've gone from nothing to the starter solenoid engages but doesn't spin the motor.
Yes, all connections are clean and tight.
Any more ideas?
Thanks.

 

[LouNY]

Is this your starter?

Have you carefully applied battery power from the large terminal on the solenoid to the small flag terminal?
Preferably using a remote starter switch such as this;

Carefully as the tractor could move when started, any jumper wire would also work just not as easily.

 

[LouNY]

Many of these tractors have a "one shot" relay in the starting system.
If you fail to start for some reason and backoff on the starter switch you have to return it completely to the off position
before you can try to crank again using the key switch.

 

[SLHADLE]

That is my starter. I have " jumpered" it. The solenoid engages but doesn't spin the engine. I removed the starter and tried it on the bench. All seems to work fine on the bench. I'm wondering if the starter could just be weak.
My system is indeed a "one shot" type. I have to turn the key off after each attempt.

 

[TractorTech]

The starter sounds like it is weak if you jumped the starter spade terminal. More correct, the solenoid may be weak to the point that the solenoid engages the starter gear, but not enough to make contact with the internal motor connection in the solenoid. Or, the contact points are burned enough to carry current to motor on the bench, but not on the tractor.

You could conduct the on tractor test as before, but also, with a battery jumper cable, apply power to the lower heavy lug on the starter to verify it is indeed the solenoid.