Hitachi EX60URG -Identification of component.

[007]

I think the design is crap and causes more trouble than its worth.
I am only guessing but i think they must have been trying to comply with a mining spec where the machine has total electrical isolation in the off state.
Use a reasonable sized wire if you are going to bypass the relay as you have described.
The only issue which needs to be checked and or dealt with is how the alternator is started.
In a motor car the alternator warning light on the dash is used to excite the alternator when the motor starts.
On your machine they use a resister between the alternator B+ terminal and the field winding.
this circuit was energized when the ignition closed the battery relay.
It might be that being bypassed the field circuit of the alt is draining your battery's in the off state.
You will have to remove a battery terminal when not running and check with a meter that is not happening.
If it is the wiring can be fudged but check first.

 

[GregsHD]

The only electrical safety circuit on a dash 1 Hitachi is the load dump relay, it's purpose is to protect the alternator from what I described above, the load dump relay is triggered when the alternator starts charging, it keeps the battery disconnect relay from disconnecting while the engine is running. It will stay connected until the alternator comes to a stop.

 

[imcase]

It might be that being bypassed the field circuit of the alt is draining your battery's in the off state.
You will have to remove a battery terminal when not running and check with a meter that is not happening.
If it is the wiring can be fudged but check first.

I don't know if it matters, but I have a main power switch mounted on the ground from batteries.

But most probably there is a problem with the Battery relay, wether it's bad connection somewhere, or the relay is broken?
Does, someone have a part number for the battery relay?

 

[007]

If the battery relay is faulty the machine and starter would have no power.
The alternator B+ gets energized from the machine side of that relay.
So you are going to have to find fuse or bad connection on that alt circuit

 

[imcase]

Finally the charging problem is solved!
It turned out to be a rather simple problem: There are - together with the battery-cables - connected two smaller cables to the battery relay. One yellow and one red. one of theese was broken just in the connection with some kind of socket. (possibly the one @GregsHD was talking about in post #39?)
Anyway we cut away the socket and connected the cables directly to the battery relay with spade connectors. This way the machine is charging again.
I hope this will be a permanent solution to the charging problem.

On the picture below you can see the yellow and red cables:

Here is the socket with the broken cable:


Thank you to everyone that has tried to help!
Hopefully you will help me again if more problems shouls occur.

 

[GregsHD]

Yes that is the fusable link I was taking about, you should reinstall a fusible link in that connection, if the wire to the alternator rubs through to ground while the machine is running it could catch fire. That is what the fusible link is there to protect against.

Pry the rubber seals out of each end around the wires, there should be large push on spade terminals, looks like the wire just broke at the spade connector.

 

[imcase]

Thanks for that answer.
It looks like the wire has broken inside the insulation of the cable, because the copper is still 1-2 cm long from that spade connector, and there is no copper inside the first few cm. of the cable.

Is this caused by some kind of fault, or could it still be that the cable has just got broken through the years?

Is it possible to replace the fusible link with a normal fuse, with a fuse holder? one for each cable? And in that case, how many Ampere should the fuse be?
If I have to replace the broken cable, is it a special kind of cable, or could i replace it with any kind?

 

[CatKC]

is it possible to replace the fusible link with a normal fuse, with a fuse holder? one for each cable?

While you 'can' replace a fusible link with a -slow blow- fuse, if you could find one that would carry the amps, it would not be as reliable (corroding / oxidizing contacts?) in a damp varying temperature area. A fusible link is just a 'smaller' piece of wire than the attaching wire so a constant heavy current will burn thu it first, as a last resort for an overload / short.

 

[imcase]

Next problem:
The overheat warning lamp came on and the buzzer sound came on just when the machine was started. The machine has been standing still for a few says so the engine is not overheated at all.
What does this lamp tell me when the engine temperature is not high?

 

[imcase]

Could it be that the temperature sensor is broken? If so, does anyone have a part number for it? Would this be easy to replace?
The coolant fluid is visible when i open the cover on top of the radiator, so there should be enough, also the engine is cold, so what is causing this problem?

Hoping for more of the valuable help that you have already given me!

 

[007]

I might be able to assist but you need to post a picture of the temp sensor or sensors on the engine to give me a starting point.
Electronics has changed the way things are done these days but on older equipment things were pretty basic.
Old design might have had one analogue sensor with a single wire which operates the temp gauge on the dash.
A second digital sensor could be there with prob two wires which closes the circuit of the High Temp Light and buzzer.
Generally older circuits were not smart enough to combine both functions off the one sensor.
Some Temperature gauges had a set of contacts which closed if the needle went high but not very common.
If you could post a wiring diagram for the machine would make it easy.

 

[ycs]

The sensor switch part number should be #4187223

 

[imcase]

Thanks for answers, so it is most likely that the sensor is broken?
Here are the pictures "007" requested:
It looks like there are two sensors on the thermostat housing, i'm not sure wich one of them does what? anyway there is just one cable to each of them.

Her is the wiring diagram that I have for the machine. not sure if it is the correct one...


Is it possible to work with the machine untill the problem is fixed, as long as the engine does not oveheat??

 

[007]

its hard to tell from diagram which sensor is which.
Usually the big one is the buzzer.
you can use the machine as long as you are sure it is not over heating.
if you pull both wires of the sensors and short them to ground and check as one will make the buzzer come on and the other will make the temp gauge got to max temp
careful not to over tighten wires on sensor as they are a little fragile

 

[ycs]

Yes the big 1 should be the buzzer, u should hear the buzzer when u short it to ground. If sensor still sound when u unplug it, mean u have short circuit on the wiring back to cab..

 

[IbrahimShenouda]

Thanks for answers, so it is most likely that the sensor is broken?
Here are the pictures "007" requested:
It looks like there are two sensors on the thermostat housing, i'm not sure wich one of them does what? anyway there is just one cable to each of them.
View attachment 180550
Her is the wiring diagram that I have for the machine. not sure if it is the correct one...
View attachment 180551

Is it possible to work with the machine untill the problem is fixed, as long as the engine does not oveheat??

Is this electric diagram same for EX60URG?

 

[IbrahimShenouda]

Hello what is the difference between EX60URG and EX60?

 

[imcase]

Does anyone know where the fault is when the machine has slack on the swing gear? It has several centimeters of slack before it starts turning. It is not a very big issue right now, but it turns out this is a dealbreaker for people to buy the machine, as i am now trying to sell it. Apparently the swing gear on Hitachi's are weak, so when they first get slack it is just a matter of time before it totally brakes.
Is it possible to say how much work it would be to fix it? How do i fix it? Or how much would it cost?
Maybe someone can help me with finding the right parts that i need to change?