Intermittent starter problem

[Timberbank]

Greetings. I have a Kubota MX5000. Intermittently, the starter fails to turn over when I turn the key on. When it fails, I tap the starter with a wrench and wiggle the wires and then it starts. It has done this in sub zero winter and hot summer weather. I want to fix the problem. My first thought is check for a cracked wire before removing the starter to have it checked. How do I bypass the ignition wire when it happens again or, how do I check the wire for continuity? Thanks.

 

[RustyA]

Typically tapping the starter then it starts is a sign the commutator inside the starter is worn/corroded and not making a good connection. Wiggling the wires then it starts indicates a bad wiring connection at the starter or wiring that might be internally corroded. By having to do both to get it to crank leaves too many variables for diagnosis suggestions. I would try cleaning all wiring connections to the starter where you are wiggling first with a wire brush and apply dialectric grease to them. Inspect those wires for signs of green creeping up insulation, this can cause a voltage drop and new wiring would be in order. If that doesn't make it crank without a love tap to the starter I would lean towards starter repair/replacement. Hope that helps

 

[PILOON]

Another elimination test is to use a jumper directly from the battery and make a direct contact at the starter solenoid and see if that activates it as normally would.
Then check all grounds.

Willing to bet corrosion somewhere is the culprit.

 

[Tx Jim]

Yrs back JD offered a kit for adding a starter relay to give solenoid activation wire more amps for better solenoid engagement. Failure of solenoid to engage starter could also be pitted contact lugs or washer inside solenoid cap
On subject of circumventing safety features of tractor wiring utilize extreme caution to be 100% sure transmission is in neutral before attempting to engage starter while standing on the ground or have someone sitting in tractor seat!!!

 

[CoyPatton]

I would live you to provide more detailed information.
Wiggle wires—too vague to know what happens.
What wire do you wiggle?
Where are you wiggling it?
What moves?
Where do you hit the starter?
How hard do you hit it?

Responses to these and other questions give details to assist with diagnostics.

One point is it is intermittent. A non existing (not saying it is not happening, but when not happening this minute it is tough to find) problem is tough to find. Most of these come out to be a faulty ground—probably most common are frame to battery contact, either end of that cable. In my experience the nest is the starter getting good ground.
Of course answers to some of the above questions could change this general assessment.