Starting issues on New Holland T7.270

[MrPerfectlyFine]

My cousin's T7.270 won't start unless we jump it, even though the battery tested okay. We're in upstate New York and it's been wet lately. Could moisture be messing with the wiring or is it more likely a ground issue?

 

[Barnsideguy]

Moisture in upstate New York can really cause problems like corroding wiring and creating shorts. It’s a good idea to check for any wet connections near the starter and battery. Don't forget to look over the ground wire too. If it’s damaged or loose that could prevent your vehicle from starting. If you find any issues clean or replace parts as needed

 

[Vodk4rickey]

If cleaning the connections doesn't fix it, the problem might be your starter solenoid. The battery has enough juice to click the solenoid (the little relay part), but not enough to actually crank the big starter motor. check if it click once? That's often mean a dead spot on the starter, a bad solenoid contact, or a weak connection that can't handle the load

 

[MrPerfectlyFine]

I plan to clean and check all the connections this week. If the problem remains, I'll test the solenoid. That should give me an answer in the next couple of weeks.

From your experience, did you notice if a weak solenoid usually shows up gradually, or can it fail all at once after damp weather?