Hitachi Ex120-5 won't start

[Jrdn7]

New to the forum so bear with me! I have a 2000MY Hitachi Ex120-5 excavator that has sat for a couple of months without use whilst there was a bigger machine in use, but now it's decided not to start for some unknown reason. New batteries have been fitted and the dash lights up, no hydraulic leaks, but it won't turn over. It appeared like the starter was jammed so that was replaced (gave trouble in the past) but stilll no joy. If anyone could shed some light on what it possibly could be it'd be great! Thanks!

[v8druid]

as Mr Frost would say .... " Hello, good evening and welcome "

It's my understanding that all the Hitachi excavators have a main battery isolator that is 'automatic' .... i.e. there's no 'key' as in a conventional battery isolator switch, manually operated.

The Hitachi's version is presumably a HD solenoid .... I'd be looking for it and seeing if it was functional.
it shuts down the main supply to the m/c, if it isn't used for X minutes/hours, so I'd presume trace-able, by following the battery's leads.

Do you have any voltage at the starter motor main pole when you try to crank it ?

There may also be a starter relay .... a lot of vehicles/plant have one to isolate the ignition switch from the heavy draw of the starter's pre-engage solenoid ... it's got a fair spring to overcome when you go to crank.

have you checked to see if the starter's solenoid is energising .... I'd assume that, as it's a new starter and if it is getting voltage, it will be engaging and making contact for the motor's supply.

Meter time Boyo ... go check those voltages

[Muz]

24 Volt supply innit .. got to be a major block stopping that

[Jrdn7]

as Mr Frost would say .... " Hello, good evening and welcome "

It's my understanding that all the Hitachi excavators have a main battery isolator that is 'automatic' .... i.e. there's no 'key' as in a conventional battery isolator switch, manually operated.

The Hitachi's version is presumably a HD solenoid .... I'd be looking for it and seeing if it was functional.
it shuts down the main supply to the m/c, if it isn't used for X minutes/hours, so I'd presume trace-able, by following the battery's leads.

Do you have any voltage at the starter motor main pole when you try to crank it ?

There may also be a starter relay .... a lot of vehicles/plant have one to isolate the ignition switch from the heavy draw of the starter's pre-engage solenoid ... it's got a fair spring to overcome when you go to crank.

have you checked to see if the starter's solenoid is energising .... I'd assume that, as it's a new starter and if it is getting voltage, it will be engaging and making contact for the motor's supply.

Meter time Boyo ... go check those voltages

Yep you'd be right there about the isolator switch, which doesn't work particularly well as if the machine is left for a while the battery will go flat anyways! I am debating fitting the spare kill switch from my Rally car to it but I can't imagine it'll like the 24v

I was wondering about the starter relay/solenoid, so I'll check if there's any power getting to or through those! Will double check the starter itself, it sounded like there was power getting to it but not enough to turn it? Luckily I've bought a new multi meter too!

Will report back back and see what I find!

[v8druid]

Yep you'd be right there about the isolator switch, which doesn't work particularly well as if the machine is left for a while the battery will go flat anyways! I am debating fitting the spare kill switch from my Rally car to it but I can't imagine it'll like the 24v

I was wondering about the starter relay/solenoid, so I'll check if there's any power getting to or through those! Will double check the starter itself, it sounded like there was power getting to it but not enough to turn it? Luckily I've bought a new multi meter too!

Will report back back and see what I find!

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Goes between the battery and the earth point .....

[Jrdn7]

One of those looks to be the job! Did some diagnostic work while work was quiet and there's power going to the starter motor, a mechanic crossed the starter motor and the machine fired up. So my limited knowledge of digger mechanics would suggest there's a block somewhere between the batteries and the starter?

Also, I learned a new name for the orange beacon, the Tinky Winky light...

[v8druid]

One of those looks to be the job! Did some diagnostic work while work was quiet and there's power going to the starter motor, a mechanic crossed the starter motor and the machine fired up. So my limited knowledge of digger mechanics would suggest there's a block somewhere between the batteries and the starter?

Also, I learned a new name for the orange beacon, the Tinky Winky light...

you refer to the w*nker magnet ... turn it on and every w*nker on the road tries to commit hari kiri in front of / under you

[v8druid]

One of those looks to be the job! Did some diagnostic work while work was quiet and there's power going to the starter motor, a mechanic crossed the starter motor and the machine fired up. So my limited knowledge of digger mechanics would suggest there's a block somewhere between the batteries and the starter?

Also, I learned a new name for the orange beacon, the Tinky Winky light...

there's obviously juice at the main +ve pole on the starter then and I assume your mechanic will have 'crossed' the solenoid supply to the main +ve pole to get it to crank ..... I doubt very much that the starter is an old inertia type of 'dog', (pinion gear)



but a pre-engage unit.



and would therefore need the solenoid energising to swing the motor over

From that, i'd say you have an issue between either; the batteries and the starter switch, the switch itself, the wiring between the switch and the starter relay, the starter relay, or lastly the wiring between the starter relay and the solenoid

easy trace with a meter .... or even a bulb type circuit tester, as your looking for voltage

good luck .... least it's proved the starter motor for you

[Jrdn7]

Here's a man who knows what he's talking about! Haha I'll start at the solenoid and work back to the batteries, hopefully it'll throw up a fault somewhere that's easy fixed! Will post my findings here so it might be a reference to someone in the future.

Between this, the Doosan wiring playing up and me pulling tracks off the Takeuchi (rubber b*astards), I think the mechanic needs a raise