Strange NH Starter Problem

[TheRanger]

So, not an expert in tractors by any means, but thought someone on here may have some sort of idea as to what's going on.

Got a NH TL100 that will not start in the morning, need to be jump started with one of the other tractors, once it's started it will start fine itself all day.

Got the battery tested, it was okay
Cleaned up the connections onto the chassis from the neutral lead of the battery as it was corroded
Got the alternator tested, it was okay
Replaced the battery with a new one as a precaution, no difference
Engineer was out for a look, it had already been jump started that morning and he couldn't see anything wrong, was starting fine, he thought the starter motor may have been on it's way out, so replaced it, next morning no difference
If I test the battery with a multimeter in the morning before trying to start it, it's reading 12.4V, so it's fully charged up

Anything I'm missing?

 

[agrimax]

A fully charged battery should be at least 12.6v after being settled a while. 12.4v is a little low.Think it's only 75% charged at that. What is your alternator producing?
Likely worth replacing both battery cables and battery terminals. The copper may be black inside the insulation creating high resistance.

 

[Lincsman]

When you say not starting, is that very slow cranking or total failure?, if its slow cranking, have someone crank it while looking for hot wires in the main leads

 

[TheRanger]

When you say not starting, is that very slow cranking or total failure?, if its slow cranking, have someone crank it while looking for hot wires in the main leads

total failure

 

[Lincsman]

total failure

In that case get someone to hold the key in start and go round tugging on the wiring loom around the engine to find loose connection (might be the key switch?), also try a jump lead replacing/ in parallel with the main starter cable in case it has an internal fault

 

[Cvx1170]

lose wires on the neutral safely switch, if it has one

 

[Dave W]

total failure

Can you elaborate. Turn the key and nothing happens at all? Does it click or do anything?

 

[TheRanger]

Can you elaborate. Turn the key and nothing happens at all? Does it click or do anything?

Sorry, it seems to turn over once when you turn the key, but fails to start.

You then attach jump leads onto another tractor, and it starts first time.

 

[Dave W]

I'd say something is discharging the battery over night. Try disconnecting a battery lead overnight and see if it's any better

 

[TheRanger]

I'd say something is discharging the battery over night. Try disconnecting a battery lead overnight and see if it's any better

We tried that as well, took the neutral off of the battery overnight. Still the same.

 

[Nearly]

@ACEngineering will sell you a fast starter motor if you decide to swap it. I've done 2 of mine.
Same symptoms.

 

[Dave W]

We tried that as well, took the neutral off of the battery overnight. Still the same.

But it starts instantly with jump leads?

 

[Derek67]

Had this exact same problem with a new holland combine, went through all sorts, ended up being the starter relay, so maybe try powering the starter solonoid direct to rule this out.

 

[Goweresque]

I would clean up the inside of the terminals, it sounds like you are not making a decent connection to the battery. The fact that when you put jump leads on (which will be connected direct to the positive and negative leads) it fires right up suggests that the battery terminals are not making a good contact with the leads. In fact as an experiment, next time it fails to start remove the leads and connect the same battery to the starter direct and see if it fires up then.

 

[TheRanger]

But it starts instantly with jump leads?

Yes started first time with jump leads every morning for the last month, except once.

One really cold morning (-4C), it didn't start with the jump leads connected onto the other tractor, so we connected a second set of jump leads onto the Manitou, it then started first time. Not sure if that's relevant or if it was just because it was a really cold morning.

 

[TheRanger]

Had this exact same problem with a new holland combine, went through all sorts, ended up being the starter relay, so maybe try powering the starter solonoid direct to rule this out.

Had a quick google search for New Holland Starter Relay's and I think I might have something similar lying in the workshop. Will try and trace the wiring to find it and replace it next time I get a chance.

 

[topcat2006]

When you start the tractor and it starts without jump leads what voltage is the battery?

 

[TheRanger]

When you start the tractor and it starts without jump leads what voltage is the battery?

The only time I measured it it was 12.4V, but that was when it wasn't starting and without jump leads. I assumed that was fine since it was a 12V battery, but from posts above it should be higher?

I'll need to check what the volts are once it's been running for a few hours.

 

[topcat2006]

What's it charging at?

 

[ACEngineering]

@ACEngineering will sell you a fast starter motor if you decide to swap it. I've done 2 of mine.
Same symptoms.

Sure could! Not looked up model but at a guess a TL100 is the FPT iveco NEF engine? If so they got Bosch starters on from factory normally and they are bad for slow cranking. Can fix that with a 4.2kw iskra.